1st method:
- on fogged glass, turn on the heating and at the place of the break the glass quickly fogs up with a spot, while the entire thread with the break does not fog up.

2nd method:
- to detect a break in the heater conductor rear window turn on the ignition and turn on the rear window defroster.
- connect one voltmeter probe to the ground of the car, and wrap the second probe in foil and move the foil along the heater conductor.
- connect the voltmeter probe to the center of each rear window defogger conductor. If the voltmeter shows a voltage of about 5 V, then the heater conductor is working. If the voltmeter shows a voltage of 0 V or 12 V, then there is a break in the heater conductor.
- to detect the break point of the heater conductor, connect one voltmeter probe to the positive terminal of the heater, and move the second probe along the heater conductor from the negative terminal of the heater. The point at which the voltage indicated by the voltmeter drops from a few volts to zero is where the heater conductor breaks.

3rd method:
- ohmmeter, in kilo mode, or better yet mego. One probe clings to one terminal of the heater, the second probe to the other terminal of the heater. Take a piece of cotton wool soaked in distilled water and move it along the threads of the heater, monitor the readings of the kilometer, the megohmmeter at the point of break, the needle will twitch.
- it is better to use an analog ohmmeter (with an arrow).
- works if there is a break in one place!

Direct thread repair:

In all the methods listed below, you must first clean the conductive strip from varnish (preferably with a bent steel wire or paper clip) until a metallic sheen appears and degrease it.

1st method (conductive paste):
- You can restore a broken rear window heater conductor using conductive paste.
- before starting repairs, turn off the rear window heating and allow time for the glass to cool.
- Using caution, strip the heater conductor and wash it with alcohol.
- use adhesive tape to mark the area to be repaired.
- Apply conductive paste approximately 20mm from each end of the damaged conductor.
- after drying the electrically conductive paste for 24 hours, you can use the rear window defroster. You can dry it at a high temperature, then you can use heating earlier.

2nd method (electrolytic coating):
- the reagents you need are copper sulfate - better known as copper sulfate (used in crop production and construction), and sulfuric acid - an electrolyte from a battery is quite suitable.
- from a tool - a piece of copper (preferably copper - not brass. Several pieces of copper wire folded into a bundle are quite suitable) tube or rod with a diameter of 6-10 mm and a strip of fabric 20-30 mm wide and about half a meter long.
- wrap a strip of fabric half its width around the end of the rod - you should get something like a tassel. You need to put a thread bandage on top to prevent the fabric from unwinding.
- preparing the electrolyte - not to be confused with the battery electrolyte - is also not difficult. Pour a couple of teaspoons of copper sulfate into half a glass of water and stir until dissolved; if it doesn’t dissolve completely, don’t worry, don’t pay attention. To the resulting solution you need to add 0.2-0.3% concentrated sulfuric acid or 0.5-1% battery electrolyte - this is about half a teaspoon of electrolyte per half glass.
- the process itself. Both terminals of the glass are connected to ground (if the glass is installed in a car and at least one heating thread is intact, nothing needs to be done), and the positive of the battery is connected to the tube with a rag. We wet the positive electrode in the solution and begin to actively and continuously rub the area where the thread breaks for 3-5 minutes. A current passes through the solution, which transfers copper ions from the electrode to the heating filament. If the thread is slightly damaged, the gap is completely covered with copper; for large gaps, the copper-plated areas should be tinned with a non-overheated soldering iron and a jumper made of thin wire should be soldered. There is no need to limit the current, because After a few seconds, the anode becomes passivated and limits the flow of current. Do not forget that the solution contains sulfuric acid!

3rd method (paint with chips):
- take a copper-brass block (graphite will also work) and use a small file to start making shavings.
- paint (can be red, to match the color of the threads) is mixed with the shavings, the proportion is approximately 50/50. You should get a dough-like mixture.
- the heating is turned on and paint is applied to the thread, having previously made a stencil from electrical tape or adhesive tape. During the process of applying paint, a hissing sound appeared from the point of contact, then it disappeared, but the thread warmed up.
- everything is done. Literally in a minute the composition hardens.

4th method (magnet and glue):
- prepare very fine iron filings, a small magnet (from the speaker) and transparent glue (type BF-2) or nitro varnish.
- attach a magnet with outside above the break point, then sprinkle sawdust on the side of the conductor, gently moving the magnet to achieve electrical contact at the break point (this will be noticeable by the heating of the strip - unless, of course, the break is in one place, otherwise more magnets will be needed).
- apply a drop of glue to the sawdust with a small squirrel brush and let the glue (varnish) dry.
- then remove the magnet and remove excess sawdust with a blade. You can reapply another layer of glue (varnish).
- enough for several years.

5th method (special adhesives):
- special adhesives for restoring heating filaments, some made in Russia
- reviews are contradictory, some like it, some don’t
- instructions for use are included with the glue
- It is recommended to add a little iodine to the glue. In this case, the glue turns out red and matches the color of the other threads

6th method (soldering):
- places of damage can be soldered with soft low-tin solder POS-18 or POSS-4-6, using zinc chloride as a flux. If a long section is damaged, it is better to solder a thin copper or silver core from the wire.

7th method (sawdust and glue):
- silver filings (for example, an alloy ground off with a file from the contact of an unusable power relay) should be poured into the fold of a piece of paper, and a drop of nitro glue should be added there. Quickly roll a cylinder with a length of 2...3 and a diameter of 1 mm with the tip of a knife and apply it to the damaged area. Then crush it to tightly compress the sawdust and remove excess.

We will consider in detail the repair of a break in one or more threads, when some horizontal strips of the rear window heater do not work. Cases when the heating on the glass does not turn on at all are no longer associated with broken threads, because 12–16 pieces cannot burn out at the same time, but with some other reasons:

• installation wires are broken;
• the intermediate relay does not work;
• the power button is faulty;

Not lit warning light in the instrument panel, clearly indicates only a malfunction of the rear window defogger button.

The place where threads break can be detected without a special tool, visually - if large breaks, wide scratches, and oxidation of damaged areas are visible to the naked eye.

Also, when it’s cold outside, on a fogged rear window with the heater on, you can find that the surface dries out near the break points, although the thread itself does not heat up.

If nothing is visible, then you will need either an indicator with a battery or a multimeter, which can certainly detect breaks, and there may be several of them in one thread.

Phase indicator with dialing function , into which the battery is inserted, is a very convenient tool; it helps out not only when you need to find broken threads in the rear window heater, as in our case, but also when searching for broken hidden wiring in the house. It is even useful for repairing such popular accessories as music headphones, because their thin wires break so often.

And everyone should have a multimeter; it is always needed in the car. Especially now, when one such device, of a simple design, without an accuracy class, is very cheap.

In general, one of the mentioned tools is enough. You will need to screw a thin wire onto the dial indicator, onto its metal handle hook. Then, the free end of this wiring is hooked onto the ground of the car, you can use the door lock open door, and the indicator itself is guided by a tip along the conductive path of the heater. You need to connect the multimeter probes for testing in the same way, do not forget to just switch the universal measuring device to DCV, 20 - voltage measurement DC with a measurement limit of up to 20 volts.

At the point where the thread breaks, the voltage will disappear when the rear window heating is turned on, which will be indicated by the indicator light going out or the absence of readings on the multimeter.

At the factory, copper conductive paths are applied to glass by electrolytic deposition in a bath of copper sulfate. But in garage conditions fiddling with reagents and sulfuric acid solutions is dangerous, and can lead to lightened spots on the back shelf, as well as the seat, and also holes in your clothes. But it’s of little use - you can only patch scratches with a homemade electrolyzer or only clean oxidized areas near large breaks.

Minor scratches can be repaired by soldering . Before soldering, to remove green oxide, just wipe the damaged surface once with a cloth soaked in alcohol or any of the available solvents. Trying to remove green plaque, Do not use a knife, scalpel, sandpaper -You will only scratch the damaged area even more.

It is recommended to use zinc chloride as a flux, but you can use any active fat, Vaseline or other special composition, which does not leave a lot of burning after soldering. Solid rosin or rosin dissolved in alcohol will not work - it leaves too much dirt.

Thin copper wire, 0.3–0.4 mm in diameter will be needed to patch wide gaps. What you need to solder is a thin copper wire, no more than 0.4 mm thick, because otherwise a thicker one with its low resistance will create more heat at the junction point than the rest of the intact part of the thread.

You can only tin the copper wire, not the ends of the torn track, since the thick tin tail may cause the coating on the glass to fall off.

The above-described repair method is sloppy and subsequently leaves a noticeable trace of tampering on the glass. There is a special two-component conductive adhesive , which costs $10-$15 in a small set. The composition is prepared by mixing the most heat-resistant cyanoacrylic glue with copper powder, strictly in the proportion specified in the instructions on the package.

You should not turn on the rear window heater immediately after applying the repair compound; you need to let the glue harden. The hardening time of the conductive composition is about 30 minutes.

The prepared conductive paste must be apply thinly , not thicker than the working part of the rear window heater thread. Just as in the case of repairs with copper wire, a too thick layer of hardened paste, having low resistance, will heat up more than the rest of the conductive path. But in general, you will get the impression that the repaired filament heats up less than others that have not been repaired.

A little trick: to conductive paste too light after drying, it matches the color of the sprayed copper tracks; you can add a few drops of medical iodine to it.

Few people know that covering the repair area on glass with ordinary transparent tape is wrong: it leaves too much sticky glue and comes off along with part of the conductive paste. The repair area should be limited horizontally and vertically narrow paper masking tape - that's the only way professionals do it. Some repair kits include a ready-made stencil, but you have to hold it with your hand when working.

Repair results

Repairs with soft solder are quick and easy , and the results last for several years. The reliability of this method has been confirmed by a large number of home craftsmen who have resorted to it, since its financial costs are kept to a minimum. The requirements are minimal: purchase a good, highly active flux and have practical soldering skills. There is only one drawback - soldering spots on the glass are visible , and you can’t disguise them.

Anyone can do it too, there are a lot of repair kits on the market, from cheap little packs to professional boxes. The quality of the repair, subject to the manufacturer's instructions, is excellent and long-lasting. Important advantage : by working carefully and having the knowledge, you can hide the repair areas so that the glass will be like new.

Homemade podiums for car speakers

Freezing and fogging of the rear window lead to a decrease in visibility, which limits control over the road situation. In the article we will consider all heating components, as well as their possible malfunctions. We'll show you how to repair a heated rear window.

How the system works

To easily find a malfunction of the rear window heater, let's look at the design of the system. All elements are presented on a schematic diagram.

1. Mounting block.
2. Heating switch relay.
3. Ignition switch.
4. Button on dashboard. There is a light inside the button that lights up when the heating and ignition are on.
5. A corresponding icon on the dashboard that duplicates information about the heating being turned on.
6. Conductive threads located on the rear window.

The operating principle of the entire system is the heating effect, which occurs when current passes through the heating element. In the rear window heating system, this is a network of conductive threads. When you turn the ignition to the 3rd position (On), power is supplied to the system power button through the fuse (in our case F7). After pressing the button, the current, lighting the control light, flows to the corresponding icon on the dashboard and back to the mounting block to the power relay. After closing the corresponding relay contacts, power is supplied (+) to one of the terminals of the system of conductive threads. The second terminal is connected to the car body, corresponding to the negative terminal of the battery. Thus, current begins to flow through the threads.

Now it’s easier for us to understand how to repair the heated rear window. To successfully repair the heated rear window of a car, it is advisable to be able to read electrical diagrams, since not for all cars you will find elements depicted as clearly as in the diagram we provide.

Malfunctions

How to find the reason

All manipulations to find the cause of the breakdown should be performed after checking the fuse. Also, often the very nature of the breakdown can suggest a path to troubleshooting.

For example, along with the heated rear window, the light in the button stopped working. It is likely that this is just a coincidence, since the light bulb could simply burn out. But the contiguity indicates the likelihood of a lack of power supplied to the button. In this case, according to the diagram above, you need to check the circuit from the ignition switch, pins 1 and 9, 2 and 4 for mounting block, 85 and 86 relay contacts, as well as the button itself.

There is no heating of the filaments, but the light in the button works after switching on. In this case, power is definitely supplied to the button, so there is a breakdown in the circuit after the switch. It is necessary to check fuse F4, the heating switch relay and the corresponding terminals in the mounting block, as well as the contacts of the heating filaments.

The glass only partially thaws, which indicates that some of the filaments have broken.

Power check

To diagnose an open circuit, you need to know. In DC current (DCV) measurement mode, you need to check sequentially whether voltage is being supplied to certain terminals.

To check the power supplied to the relay, it must be removed from the mounting block. To check, you will need a multimeter (in DC mode, up to 20 V) or a tester. Turn on the heated rear window. If there is current at the 85th and 86th relay terminals, then there is a fault in the relay itself or in subsequent elements of the circuit.

To check the functionality of the relay itself, it must also be removed from the block.

You can use a multimeter in resistance measurement mode or the so-called continuity test. The lighting of different lights helps to determine + and -; Some devices have sound.

To check the coil located in the relay, connect the probes to pins 85 and 86. If the multimeter shows infinite resistance and the red indicator in the control does not light up, indicating a short circuit, then the coil has burned out or the contacts have become unsoldered. For subsequent testing, connect power from the battery to pins 85 and 86. After a click, indicating that the coil is working, contact should appear between pins 30 and 87.

If you do not want to check separately the relay and pins 85, 86 in the mounting block, check if there is voltage at pins 10 (Ш9) and 5 (Ш8). The presence of voltage will be a fact that the relays and tracks of the mounting block are fully operational.

If, when troubleshooting, you find oxidation of the contacts, clean the surface with sandpaper or a file. The heater repair will be completed.

Finding a broken heating element

There are many ways to detect broken conductive threads. To search, you can use a multimeter in resistance measurement mode. You need to measure the resistance at the beginning and end of each thread. The value should be approximately the same. If the value 1 lights up on the screen, this will indicate a break. You can connect to the terminals of the battery threads. The multimeter must be switched to DC current measurement mode. Attach the positive probe to the positive terminal of the heating element, and apply the negative probe to the middle of each thread. The value should be equal to half the battery charge.

To localize the location, measure in the same way, starting from the edge of the thread. Place the probes at a distance of, for example, 10 cm and move towards the edge of the thread. To avoid damaging the tinting excessively, you can solder needles to the leads of the probes. This way you can pierce the film unnoticed and not harm the threads themselves.

DIY repair

Repairing the heated rear window is impossible without a special conductive compound. To attach the terminals to the element, you can use special glue. To restore threads, there are special repair compounds. Their cost is quite affordable, and you can find them in almost every auto supply department. There are also methods self-made conductive compounds. Heater repair occurs as follows:

• remove the tint from the broken area. Use a ruler and a utility knife to carefully cut the film only around the perimeter of the thread break;
• degrease the surface;
• apply masking tape, leaving space inside for the repair compound;
• apply conductive glue;
• tear off the tape. Do not wait for the composition to dry, as there is a possibility that the layer from the repair area will subsequently come off along with it.

Do not apply too thick a layer, as this will reduce the resistance and, as a result, the temperature in the repair area.

A heating element repaired in this way will continue to serve you faithfully.

A good review is essential for safe operation car. IN autumn-winter period Changes in air temperature cause the windows to fog up, and visibility through them deteriorates. The issue of glass transparency is especially relevant at night, when visibility is already poor.

An effective way to combat fogging of car windows is to heat them. Windshield, as a rule, is heated by directed flows of warm air. The rear window and door mirrors are usually heated electrically. Conductive tracks made of high-resistivity metal in the form of thin ribbons are applied to the surface of the glass on the side of the car interior. When electric current passes through them, thermal energy is released. The glass heats up and the water evaporates. After a few minutes the glass becomes transparent.

Electrical diagram for connecting the heater

To successfully diagnose and repair the rear window heating system of a car at a professional level, you need to know electrical diagram connecting the heater and presenting the principle of its operation.

The photo shows typical diagram connecting the car's rear window heater to the on-board electrical wiring. Let's consider the principle of its operation.

The supply voltage from the positive terminal of the battery through the ignition switch and fuses is supplied to the heater switch and to the 30 (or 87) power contact of the relay. The negative terminal of the battery is connected to the car body, one of the glass heater terminals is also connected to the body. When you press the heater power button, voltage is applied to the relay winding, the relay is activated, the power contacts close and connect relay terminals 30 and 87 to each other. The current enters the heater, flows through a group of parallel-connected filaments and returns through the car body to the negative terminal of the battery.

Rear window defroster malfunctions

The operation of the rear window defogger is not paid attention to until the glass fogs up or becomes covered with frost. After turning on the heater, it suddenly turns out that after a few minutes the glass did not become transparent or visibility appeared only through part of the glass. Depending on the external manifestation, even without measuring instruments, one can immediately make an assumption about the cause of the failure.

Please note that the heated rear window and rear view mirrors of the car can only be turned on when the ignition key is turned to the ON position. In some car models, the heater can only be turned on when running engine. This is done to prevent severe battery discharge, since the rear window heater, depending on the car model, consumes a current of 10 A to 25 A. For comparison, one car headlight consumes a current of only 5 A.

The heater does not turn on

If the indicator on the button for turning on the heated rear window does not light up after pressing it, then most likely the fuse has blown or the button itself is faulty. If the indicator lights up, but not a single thread heats up, then the cause of the malfunction may be the relay or connectors connecting the heater to the electrical wiring. In this case, using the documentation for a specific car model, it is necessary to determine the location of these parts and replace the one that failed. It is not always possible to quickly find the installation location of the relay, but there is a way to check its serviceability indirectly, which will be discussed below.

The glass is slowly fogging up

Sometimes there is a case when, after turning on the heater, the glass fogs up for a time significantly exceeding several minutes. In this case, if it is not very cold outside, the reason may lie in poor contact of one of the connectors of the electrical circuit. As a result, the contact resistance increases, the current is limited, and as a result, the power released on the glass heater filaments decreases. To check such a malfunction, it is necessary to measure the voltage at the input terminals of the heater and battery using a DC voltmeter (multimeter or pointer tester turned on in the DC voltage measurement mode). The voltages should not differ by more than one volt.

Horizontal streaks of fog remain on the glass

And finally, the most common case of malfunction of the rear window heating system of a car is the breakage of one or more heater threads applied directly to the glass. This type of malfunction is immediately visible by the horizontal stripe of remaining fog on the glass after turning on the heater.

The conductive paths on the rear window have low mechanical strength and are easily destroyed when exposed to impact. Therefore, it is prohibited to remove frost and ice from glass using a scraper. Only wipe with a soft cloth is allowed. It is also necessary to ensure that when transporting long items they do not rest against the rear window. As a rule, individual heater filaments stop working as a result of their accidental mechanical destruction. In the area of ​​the damaged thread, after turning on the heating, streaks of sweat or frost remain.

When renovating an apartment, I was transporting floor skirting boards in my car and did not notice how one of them rested against the rear window. After a while, when I needed to warm up the rear window, I saw the result of my carelessness. The two heater strips running through the middle of the glass did not heat up, which significantly impaired the view of the road. Upon visual inspection, one gap of about 1 mm wide was found on the non-functioning strips, as in the photograph. The question arose about the need to repair the rear window defroster.

How to find the location of a broken glass heating filament

It is not difficult to determine which heater thread is broken, since in the area where it passes, fogging does not disappear when the heater is operating. Therefore, in order to easily find the faulty thread during repairs, it is advisable to count the threads from top to bottom and remember which one is by number in the break, so that later, by visual inspection, try to find the place of its damage. But the thread break is so small that it is impossible to visually find it. Then a DC voltmeter, ohmmeter or voltage indicator will help in your search. To quickly find the location of a malfunction in the heating element, you need to understand how it works and works.

The design of the heating element of the glass heating system

The logical question is, why does it happen that only one or several threads in the heater do not work, while the rest work? To answer this question, you need to familiarize yourself with the design of the heating element.

The heating element of the rear window of a car is designed as follows. On the sides of the rear window there are two conductive busbars 1 and 2. Threads made of high-resistivity material are connected to these busbars. Each thread has a resistance of about 10 ohms. The number of threads depends on the height of the glass. Thus, each thread is a separate heating element, the operation of which does not depend on the others. A parallel connection scheme of heating elements is used. This circuit design ensures high operational reliability of the heater, since the breakage of one or more threads does not lead to a complete cessation of its operation.

Finding a broken heater filament using a voltmeter

To work, you will need any DC voltmeter with a measurement limit of 15 V. Any pointer tester or digital multimeter. Before starting work, you need to turn on the heater.

Since one of the heating element busbars is connected to the car body, the negative terminal of the voltmeter can be connected to the car body; any screw or bolt screwed directly into the body will do. The most convenient way to connect to the trunk lid lock bracket is with an alligator clip.

Since it is difficult to visually determine whether the heater is heating with transparent glass, touching the positive probe of the voltmeter to bus 1, and then to bus 2, you will immediately understand this. On bus 1 there should be a voltage of +12 V, and on bus 2 - 0 V. It is quite possible that the left bus in your car will be connected to ground, and the supply voltage will be supplied to the right bus. If there is no access to the tires, then measurements can be taken by touching with a probe any of the threads at the points of connection with the tires, that is, at the points where they exit the rubber seal. In the photo these are points 1 and 5.

Using a voltmeter it is easy to determine which part of the heating system is faulty. If the heater is turned on, the power indicator on the button lights up and there is 12 V on bus 1, but there is no heating, which means that the electrical wiring to bus 1 is working. If there is no voltage on bus 1, then there is a bad contact in the supply voltage terminal on bus 1, or the relay is faulty. If 12 V is present not only on bus 1, but also on bus 2, then you need to look for a bad contact in the terminal connecting the wire to bus 2 or the circuit connecting the wire to the vehicle ground.

Finding the location of the thread break

After checking the supply voltage supply system to the heater, you can begin to determine the location of the heating filament break. The thread is a tape resistance of about 10 ohms, and therefore the voltage at different points has different values. Therefore, at point 1 the voltage will be equal to 12 V, at point 3 - 6 V, and at point 5 - 0 V. Therefore, even without knowing which thread is broken, it can be easily found by measuring the voltage value at the midpoints of the length of all threads. On broken threads, the voltage will be 12 or 0 V. If the voltage is 12 V, then the break point is on the left, and if 0 V, then on the right.

Now it is enough to slowly move the probe towards the break, in the place of a sharp change in voltage there will be a break. For example, in the photograph this is the section of thread between 6 and 7 points.

Finding a broken thread using an ohmmeter

Using a multimeter or pointer tester in "title="How to measure resistance">измерения сопротивления тоже успешно можно найти место обрыва нити. Включать обогреватель при поиске омметром не нужно, но проверить исправность системы подачи питающего напряжения на нагреватель, кроме проверки цепи подключения к массе, не получится.!}

If the broken thread is not known, then you need to connect one end of the ohmmeter probe to the ground terminal, and with the other end, in turn, touch the middle of the heater threads. The thread on which the ohmmeter shows resistance is twice as high and will be broken. For reference, the resistance on whole threads relative to bus 1 or 2 should be 2-3 ohms. In case of a break in the thread, the ohmmeter will show 4-6 ohms.

When the damaged thread is found, you need to move the end of the probe from the center in any direction. If the resistance increases as the probe moves towards bus 1, then the break is located in the gap between bus 1 and the point of contact of the probe. For example, in the place indicated by points 1 and 2. As soon as the probe passes the break point, the resistance will sharply decrease several times. If the resistance decreases, it means that the place where the thread breaks is located between the probe and bus 2. For example, in the place indicated by points 3 and 4. Then you need to move the probe towards bus 2, and when the resistance drops sharply, the break point will be at this point .

Finding the location of the thread break
using an Automotive Probe Tester

If you don’t have a voltmeter or ohmmeter, you can find where the heating element filament breaks using a homemade automotive probe tester, consisting of just one LED and a current-limiting resistor. I made such a tester for myself a long time ago, although I have any measuring instruments at my disposal. A homemade car tester is always in the glove compartment of my car and I have had to use it more than once.

Finding the location of a broken thread using a probe tester is not much different from searching with a voltmeter. In this case, the indicator will not be an arrow or numbers, but the glow of an LED.

Before you start searching for a damaged thread with a probe, you must apply supply voltage to the heater. First, the presence of voltage on bus 1 is checked, the LED should light up, if the LED does not light up, then the fault lies in the supply voltage supply circuit. Next, the voltage on bus 2 is checked; the LED should not light up; if it lights up, it means there is a contact failure at the point where the wire is connected to the bus or the car body.

To find the break point of the heater filament, you need to slowly, lightly touching the filament, move the tip of the probe along it. At the point at which the LED goes out or lights up there is a thread break. For example, at point 6 the tester LED will light up, but at point 7 it will not. In my case, the thread breaks were large and the tester was only useful for checking the quality of the repair.

Methods for repairing heating element filaments

There are several ways to restore the functionality of a heating filament at home.

Using conductive pastes and adhesives

The easiest and most effective way is to use special repair kits, such as DONE DEAL DD6590, designed to repair rear window defroster threads and contacts by both amateurs and professionals. The good thing about this method is that it does not require tools or materials. It is enough to apply a little conductive paste from a syringe to the site of the thread break according to the attached instructions, wait until the paste hardens and the repair is completed. But this set costs more than $15.

The second method is similar to the previous one. But instead of a proprietary set, they use purchased conductive adhesives, for example, Elekont, a Moscow manufacturer. Glue is applied to the place where the thread breaks, overlapping the entire part of the thread by a centimeter on each side. To obtain a neat look, use a stencil made of electrical tape or adhesive tape. For reliability, the glue is applied twice. It is advisable to lay a piece of tinned copper wire with a diameter of 0.3-0.5 mm between the layers of conductive glue.

There is an opinion that conductive paste or glue for repairing glass heater filaments can be made independently by mixing paint or glue with brass filings in a one-to-one ratio. The resulting composition is applied in a thin layer through a stencil to the place where the thread breaks in several layers. But the reliability of this technology has not been confirmed by practice.

Electroplated copper deposition

Another method is galvanic copper deposition. The heater filament repair method seems attractive. But from personal experience I can say that the reliability of such coatings at home is low. So I was hesitant to use this technology.

Using soft soldering

Widespread mechanical method restoring the integrity of the rear window heater threads using soft soldering. I have tested the reliability of this method when repairing rear window heating filaments in my own car. Below step by step instructions, written based on my experience, will allow you to easily repair the heater filament yourself in just a few minutes with virtually no financial costs.

On the advice of theorists on the Internet, I made a big mistake and tried to clean the thread with sandpaper. As a result, instead of a break in the thread 1 mm wide, there was a break more than 1 cm in size. The thread strip is very thin, only a couple of tens of microns and can be erased instantly, even with the finest-grained sandpaper. The heater threads are already not covered with anything, and it is enough to degrease the soldering area using a rag soaked in alcohol or acetone.

If the width of the thread break is less than 1 mm, then you can do without soldering an additional conductor. In my case, the width of the gap was large, and I had to first prepare a piece of copper wire for the jumper. A current of about 1 A flows through one thread of the heater. Based on this, we select a wire with a cross section of 0.17 mm 2 from the wire cross-section table, which corresponds to a diameter of 0.45 mm. The length of the copper jumper must be equal to the width of the thread break plus 2 cm. Before soldering, the jumper must be tinned with a thick layer of POS-61 tin-lead solder. There is no need to tin the heater thread.

In order for the solder to reliably adhere to the heater thread, before soldering the jumper, you need to lubricate the thread in the soldering zone with a thin layer of zinc chloride flux using a brush.

Next, the jumper is pressed against the heating thread and heated for one second with a 12 W soldering iron. The hand is moved to the side. The jumper should be held on by a thread. Trying to tug it to check the quality of soldering is unacceptable; it will fall off and also tear off a piece of the heater thread. Unfortunately, this has been verified empirically. As a result of experiments, I eventually had to solder a jumper 5 cm long.

After soldering one end of the jumper, the second is pressed tightly to the thread and is also heated with a soldering iron. After soldering is completed, in order to remove residual acid flux, the glass is thoroughly washed with water.

To top it off for reliability, although this is not necessary, I covered the soldered jumper on top with transparent “Moment” superglue based on cyanoacrylates, the heat resistance of which is about 70°C. The heater does not heat up above this temperature.

As a result, the time to repair a broken thread with your own hands, taking into account all the preparatory work, was no more than ten minutes. The repaired threads have been in service for more than three years.

When creating passenger car Designers pay great attention to the glazing of the car. In design vehicle glass plays an important role. They protect the driver and passengers from wind, dust and dirt. They serve as a soundproofing barrier, which allows people in the cabin to talk without strain.

Their shape determines visibility from the cabin and the driver’s ability to properly control traffic situation. To achieve this, various modifications are made to the windows, including heated rear windows.

The system that helps clear the rear window of ice, snow or fog is not very complicated in design. The electrical circuit in general terms can be depicted as follows:

• C - generator.
• E230 - OZS system switch.
• J519 - on-board electrical network control unit.
• Z1 - heating element of the OZS system.

Although on different models cars and there may be some differences, however, if we consider it in detail, then in principle it includes the following main elements.

1. Mounting block.
2. Ignition switch.
3. Heating switch ZS.
4. Indicator lamp signaling the activation of the OZS.
5. Heating element of the OZS system.

K6 - additional relay.
K7 - OZS switching relay.
A - connection to power systems.

In addition, the system has fuses, terminals and wires that connect all elements into a single whole.

When the ignition key is turned, the OZS is turned on by pressing a button, to which power is supplied through an additional relay K6. At the same time, the rear window heating relay K7 is activated, the heating element is connected and at the same time the control light comes on.

The design of the heating element on the rear window may also vary. In the standard version, it is a mesh of thin metal nickel threads, which are connected by two conductive busbars located with opposite sides. On one side, a 12V current is supplied to the bus, and on the other, the bus is shorted to ground. Such devices are attached to the glass using special glue.

On some car models, the heating element is applied to the glass using spraying, for example, aluminum. A thin film with good light transmission is attached on top of this coating using glue that conducts current.

Troubleshooting in the OZS system

If you find signs that the rear window heating is not working, you must carefully check the entire electrical circuit of the vehicle's EOS system.

The first thing to check is the serviceability of the fuses. So, for example, on a VAZ-2110 these are rear window heating fuses F4 and F7, which are located in the mounting block. Their malfunction may occur due to a manufacturing defect, short circuit or a power surge in the on-board network. The faulty fuse needs to be replaced, for which it must be removed from the mounting block.

Next, you need to check the terminal connections in the OZS system. When operating a vehicle, all equipment is affected by strong vibrations. As a result, the contacts may be damaged or a terminal may become disconnected or loose.

The heated rear window relay must also be checked. Breakdown of the relay is possible when the wire in the working coil of this part breaks or due to burnt contacts, due to a manufacturing defect or short circuit. To check it, the relay must be removed and checked using a tester. If this part malfunctions, it needs to be replaced with a working spare part.

You should also check the rear window heating contact. A conductive element is attached to the rear window using glue, which is a contact to which an electric current is supplied through a wire, which is transmitted through this contact to the heating filaments.

In this place, the wiring may break or, due to the fact that the glue was of poor quality, the contact element may peel off from the glass.

Quite often, the failure of the rear window heating is caused by a break or damage to the threads in the heating element on the rear window. This is detected by visual inspection or instrumental analysis. Visually, you can only detect obvious damage to the thread by establishing a gap between the damaged ends.

It is possible that for some repair work The car suffered mechanical damage to the surface of the glass on which the heating element was attached using glue.

However, the main tool for diagnosing this malfunction is a voltmeter or ohmmeter.

They allow you to accurately identify an area with faulty threads, even if this break cannot be visually detected.

The procedure for repairing a faulty OZS system

Having determined the reason why the rear window heating does not work, you can begin to repair this system.

1. If the fuses or relays of the OSZ system are faulty, then the faulty parts must be removed. Replacing them with new, functional ones is not difficult. The main thing is that they are installed as indicated by the on-board electrical system diagram.
2. In the case where the culprit of the damage in the OZS system is the terminal connection, restoring the heated rear window is also not difficult. It is enough to clean the contacts in the terminals. The terminal box may need to be replaced, but this will not take much time either.
3. If the glue that was used to attach the contact on the rear window turned out to be of poor quality and peeling occurred, then in this case you need to buy a new high-quality conductive glue. Remove the layer of old glue from the peeled contact using a napkin with an alcohol solution. Then apply a layer of new connector and glue the contact in place.

1. If a wire is torn off on one of the buses, it is necessary to solder this wire to the old place using the connection diagram. The procedure is as follows:

• remove the remnants of old solder from the wire, stripping the end; in addition, you need to clean the connection point on the bus;
• Using a brush, apply rosin paste as a flux to the cleaned surfaces of the bus and wire;
• Apply solder containing three percent silver to the cleaned and rosin-coated wire core;
• solder the wire to the bus, while avoiding overheating of the surfaces.

1. The greatest care when repairing the heated rear window with your own hands is required if a break is detected in the conductive threads of the heating element of the OZS. To make this work easier, special kits for repairing this system are commercially available. To correct the damage, perform the following steps:

• in the area of ​​the rupture, clean an area six millimeters long in each direction from the damage site;
• wipe the cleaned area with a napkin or cloth soaked in alcohol or an alcohol solution;
• On both sides of the damaged thread, stick thin strips of repair adhesive tape or ordinary construction tape, if there is no repair kit. Avoid sticking adhesive tape onto nearby threads to avoid damaging them;

• if you have a repair kit, mix the hardener with a silver-colored composition, which, after application, will act as a conductive thread. After mixing, apply this composition with a stick or brush to the damaged area, closing the circuit.

• if there is no repair kit, then the role of a special mixture will be played by glue, which conducts electricity well; it can be applied with a brush, being careful;
• after repairing the damage, you need to give time for the glue or special mixture to harden; you can use a hairdryer to speed up this process;

• after the conductive strip has dried, you must carefully remove the self-adhesive tape; to do this, it is best to cut it with a knife at the point where it adjoins the thread being repaired, so as not to damage it when removing the tape;

• After the work has been completed, you need to check the functionality of the OZS by starting the car engine and pressing the OZS power button.

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