The rear window heating does not work: reasons and solutions. rear window heating repair

Why do the heating, heater and wipers fail at the same time?

Separately, situations stand out when the stove, wipers, and heated rear window do not work. Sometimes, along with these systems, the washer also stops working.

Ways to eliminate the defect:

To quickly solve the problem, just replace the fuse;
When examining a faulty unit, it is easy to notice burnt tracks, which can also be soldered.

What to do if the threads break, how to determine the defect

If the rear window heating stops working, you need to inspect the device to understand the cause of the problem. Most often, the main problem is a violation of the integrity of the threads - the contact necessary for the passage of current and heating disappears.

Determining the location of the damage:

When the glass fogs up, you need to turn on the heating, which will make it easy to identify non-working elements. It is noteworthy that the performance of the remaining components is not affected, since a parallel design is used.
Having cleaned the surface, we proceed to inspection. If there is a significant gap, the defect is easy to detect.
In case of invisible damage, use a magnifying glass or multimeter.

Diagnostics using a multimeter begins by connecting the clamp to the housing. Then, using the second tip, you can begin the process of searching for the damaged area.

To find a break, you need to determine the resistance by checking the threads in the central part. There should be indicators of no more than 2–3 ohms. If a resistance of 6 ohms is detected, then there is a defect. Having identified the thread, you need to carefully check it, measuring every 1-2 cm.

Subtleties of heating system repair

Broken threads are the most common problem. Car owners often wonder why the rear window heating stopped working. The problem lies in the threads - they are quite fragile and easily damaged during active friction. To remove dirt, it is better to use a soft cloth and special products. If you have to work with a scraper, you need to do it carefully.

How to troubleshoot:

Using a complex that includes a syringe and conductive paste, it is easy to restore the integrity of the area. It is enough to apply a thin line of the composition to the damaged area. Drying occurs within a few minutes, sometimes you need to wait a day - it all depends on the product. You need to turn on and check the functionality of the system after complete drying.
Choosing a conductive adhesive is a more affordable solution. The glue must be applied in two layers. And between them it is advisable to lay copper wire with a diameter of 0.3 mm.
Applying a mass of paint and non-ferrous metal shavings. The procedure is performed with the heating on. While covering the damaged area, a hissing may occur, which soon goes away. Drying time – 30 minutes. It is advisable to begin operation within an hour.

Attention:

Another restoration method is soldering. This is the most reliable method, and if the damage is small, soldering is carried out quickly, without wire.

Carrying out work for more serious defects:

wire with a cross section of 0.17 mm2 is used;
its length should be slightly larger than the damaged area;
the edges need to be tinned;
degrease the working surface;
coat the thread with zinc chloride flux;
Having completed the preparation, we begin to work, pressing and soldering the wire into the edges of the threads;
12 W power is used;
When finished, you need to check the soldering area and clean the surface from flux residues;
the treated area is covered with a heat-resistant adhesive composition.

Can the air conditioning system work for heating?

A properly functioning air conditioning system keeps your car comfortable during hot weather. However, even in winter the air conditioning must be turned on. During operation of the device, the moving elements are lubricated. By running the air conditioner during the cold season, you can quickly defog the windows.

When thinking about how an air conditioner works for heating, it is worth noting that in winter, when the air outside is cold, the system cannot start. But when you press the button for heating the mirrors or windshield, the system is activated and will act as a heater.

How it works:

In the summer, when freon evaporates in the condenser, the outlet temperature is 10–12 degrees.
When started in winter, the indicators remain unchanged, and this is enough for sweating and thawing.

Damage to threads

Electric strips act as current conductors, heating up slightly due to resistance (the strips are connected in parallel - the voltage is distributed evenly). If even one heating strip is damaged, the current stops circulating in the system - the heating does not work.

To restore the heating strips, you will need to buy a special repair kit from a car store (do not buy the cheapest one, so as not to run into a low-quality product). The set includes:

special glue with high electrical conductivity (choose by color so that the “restored” area does not stand out);
a brush for applying it;
tape to mark boundaries.

Find the location of the chain break (often mechanical damage). Study the instructions for the restoration kit, pay attention to the drying time and the recommended method of application. Prepare the damaged area for repair - wipe it with alcohol using a lint-free, clean rag (remove dirt and grease). Apply strips of tape in the area of the tear on both sides of the tape (leave the appropriate width). Apply the special product in several layers (see the instructions for the quantity). Let the glue dry - often a day is enough. After this, remove the tape and check the operation of the unit.

This method is suitable for repairing rear window heating in domestic cars (for example, VAZ 2114, VAZ 2112, VAZ 2107, VAZ 2109, Lada Granta).

There are two more alternative methods for restoring a break:

Using metal filings. You will need sawdust, a magnet and clear glue (preferably some tape). Description of the process: attach the magnet to the back side, pour sawdust onto the damaged area from the inside. Place tape under the bottom of the strip to prevent any metal shavings from sliding off. We fix the material on top with glue. Let it dry. Ready!
The point here is that they use a mixture of non-ferrous metal shavings and paint. This substance should be identical in density to plasticine. Next, fix the tape, as in the previous version, and heat it up. Apply the material to the damaged area and wait half an hour (hissing is normal). Allow the glass to cool for another hour before using the heating fully.

Features of foreign cars

Often, in imported cars (for example, Golf 3, Chevrolet Cruze or Lanos), the rear view mirror is heated in conjunction with rear heating. The work is carried out according to the following scenario: when the stern is activated, the mirrors are heated in parallel.

The problem often lies in a broken relay or fuse.

The heater may include several fuses, it is important to find the “culprit”

We would like to emphasize that the control electrical board may also fail. It has a short operational life due to breaks and broken contacts.

Tips from experienced drivers:

ice on the glass, failure of the “on/off” button, lack of indicator signal - most likely, the adjustment of the rear window heating relay is broken. Look at ground, switch, fuse and voltage;
there is no heating, but the light is on - no U power. The problem is in the contacts;
if heating does not occur completely, look at the threads (we described the repair methods above);
In winter, the surface may freeze even with functioning heating. In this case, first clean the glass mechanically.

To diagnose and repair the systems of your car, you can always contact a car service center. The Uremont.com portal offers many tools for finding a suitable workshop:

How does the heated rear window work?

All schemes for heating the rear window of a car are similar and have practically no significant differences from each other. AvtoVAZ models, as well as imported cars, are equipped with the same type of design and operating principle. Thin tracks - conductive threads - are applied to the surface of the rear window. The electricity passing through them causes them to heat up. On the outside of the glass, snow and ice quickly melt, and the inside of the surface gets rid of fogging.

Heating circuit

Before identifying device malfunctions and trying to eliminate them, you should familiarize yourself with the heating circuit and understand the components necessary for its stable operation.

Car rear window heating circuit

Explanation of the scheme:

1 - conductive threads;
2 — indication on the instrument panel;
3 — on/off button;
4 — ignition switch;
5 - relay;
6 - mounting block.

In the video you will learn how to repair the heated rear window yourself. Video provided by EXPERIMENT _ TV.

How to repair the conductive layer? Method No. 1

You can do this yourself. To do this, you do not need to dismantle the glass. All you need is to purchase a special conductive paste (this is available in auto stores or on the market) and apply it to the damaged area

It is important to prepare it carefully. To do this, carefully clean the varnish from the surface and degrease the area with alcohol (use a piece of soft rag)

Next, we clean the ends of the damaged threads. We apply adhesive tape or electrical tape to its upper and lower parts so that there is a small gap (no wider than the thread itself). We apply a special adhesive into it. After a day, the composition will completely dry out. Next, you can remove the remaining tape and check the system for functionality. If the heating works only partially, it means that the break occurred in several places. Find the second place where the thread is damaged and treat it with a conductive compound using a similar principle. That's all. We will also consider the old-fashioned method of repairing threads.

Causes of problems with heated rear window

Causes of OZS malfunctions:

Iced glass, a non-working power button and the absence of a signal from the lamp on the instrument panel indicate a malfunction in the control of connecting the OZS relay. The driver must check the ground, fuse, power button and control voltage. If there is no heating, but the power button is lit, this indicates that there is no supply voltage

Check the operation of contacts that may be subject to oxidation, ground, fuse and voltage on the heating element. If partial heating is observed, pay attention to the OZS threads. Their rupture requires repair.

Glass can freeze even if the heating equipment is fully operational

This sometimes happens during severe frosts. In order for the heating element to cope with its task, it is necessary to first clear the glass of ice.

How to challenge a fine from a photo/video camera

It is possible that you receive fines with photographs for violations committed by a person who has the right to drive a vehicle with you. In this, as well as in other dubious cases, you can challenge the fine from the camera by contacting TsAFAP - the center for automatic recording of offenses. By the way, the person who was driving the vehicle at the time of the violation can also be brought there. If this person confirms what you said, then the decision is made against him, and yours, accordingly, is canceled.

In the center you will watch a video of the moment your car violated traffic rules in excellent quality, and in color. With the help of this video, you can also examine other controversial issues related, for example, to running into a stop line, etc. If the driver believes that the traffic police fines with the photo were issued to him unreasonably, then he will need to write a free-form application-complaint to TsAFAP. By the way, it can also be sent by email, after which the driver will be invited to an administrative review.

If, after a second joint review of all the details, the driver does not agree with the decision, then the case is sent to court, where the judge will make a decision after watching the same video. Usually in such cases the validity of the fine is confirmed, and if you do not pay it within 70 days, the fine will become unpaid.

But you are unlikely to be able to challenge a speed fine from a camera (except for the method described in the video below), even if you have data from a GPS dash cam at the time the violation was committed. These devices are not certified speed measuring devices, and in court you will be believed less than data from a video recording camera. Therefore, obey the speed limit, and if you do receive a fine, the validity of which you agree with, pay it on time.

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 vehicle 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 the engine is running. 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 tracks 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.

Scheme of work

To know how to restore the heated rear window of a car and approach the repair with a high level of professionalism, study the principle of operation and the electrical wiring diagram. From the + terminal of the battery, power is sent to the ignition switch, then to the fuses and, lastly, to the controller. After this path it follows to the power contact of the relay. The vehicle body is connected to the negative terminal of the battery. Activation of the heater supplies voltage to the relay winding, then the power contacts are closed, and the relay terminals are also connected. The current flows through parallel-connected heater strips and then reaches the negative terminal through the body of the machine.

Remember, activation of the heater is only possible with the ignition key activated.

In some cases, a running motor acts as a factor predisposing to activation. This feature is due to the fact that the battery should not be discharged prematurely, and taking into account the characteristics of each car brand, the consumption volume of this system can be 10-25 A.

How to dilute antifreeze concentrate

Do not forget that antifreeze is a liquid that should not only cool the engine, but also keep it in working condition, cleaning it from corrosion elements and protecting it from rust using the additives contained in the composition. If you dilute antifreeze concentrate with tap water, there is a high risk of not only reducing the effectiveness of the additives, but also introducing microelements into the antifreeze that will negatively affect engine operation and lead to rapid corrosion or other troubles. Moreover, magnesium, calcium, chlorine and other elements found in regular tap water will clog the small passages in the engine, reducing cooling efficiency.

Accordingly, to dilute the antifreeze concentrate, you must use pure distilled water, which can be purchased at a car or hardware store. There are no harmful impurities in such water.

Electric glass heating

We know that the driver's visibility depends on the viewing angle, weather conditions and, of course, the quality of the glazing

auto glass of a car. During cold weather in Moscow, car windows often fog up, when driving minus 2 - minus 5 during wet snow, an ice crust forms on them and, as a result, the car becomes like an uncontrollable car, due to the fact that the driver is almost deprived of visibility. At the same time, the safety of people both inside the car and ordinary Moscow pedestrians who are unlucky enough to be nearby is significantly reduced. Electrically heated car windows are designed to combat fogging, along with other systems. Climate control or a simple air conditioner does a good job of fogging up windows, but they are almost ineffective in winter and also when dealing with ice. Most modern cars have not only electrically heated rear windows, but also heated windshields. This has become a good practice for leading manufacturers over the last 3-5 years.

Restoring Heated Strips

So, the rear window heating does not work, what to do and where to start the repair. The first thing you need to do is get a high-quality repair kit for restoring electrical filaments. You can purchase it at any auto store or car market at a very reasonable price, but not less than three hundred rubles. Kits that are too cheap have low quality materials and simply may not solve the problem.

The repair kit includes glue or varnish with high current conductivity, a brush for applying it, as well as adhesive tape for marking the boundaries of the conductor. When buying a repair kit, you need to decide on the color of the conductive agent so that it does not differ from the color of the tapes on the car.