Car rear window heating often fails. In most cases, it refuses not completely, and fragmentary: individual zones or heating threads do not work. To replace in this case the glass is completely irrational.
There are various ways of self-repairing threads and other elements of the heating of the rear window of the car in order to restore their performance. Consider them in this article.
Principle of operation
The heating of the rear window of the car occurs due to the heating of special filaments deposited on the glass when direct current flows through them. The threads are made of a conductive material of low resistance. The total current of the rear window heater is about 10 amps. The number of threads is about ten. Thus, a current of approximately 1 amperes flows through each thread. It is easy to calculate according to the law of Ohm, that the resistance of the thread is about 12 ohms.
The nithe of the heater is applied with the technological process of manufacturing the rear window at the factory in several ways:
- electrochemical;
- vacuum spraying (the most reliable method);
- sticking.
The chemical composition of such threads may include various elements, alloys and composite materials: resins, copper, graphite, nickel, chrome, tungsten. The manufacturer does not declare production technology, so for each technology (heated glass) you have to select the appropriate way to restore performance.
For example, a soldering is practically impossible if the threads were sprayed in vacuo carbon composition. In this case, only conductive adhesives are effective.
Connection scheme
Usually, the rear window heating thread is supplied to the battery voltage through the fuse systems, switches and relays according to the scheme below.
In some models of cars, the rear window heating is possible only with the engine manner. For this, another blocking relay is provided. The fuse mounted on the heater power supply chain typically has a nominal value of more than 15 amps.
Signs of malfunction
The main signs of the heating of the rear window:
- does not turn on completely;
- turns on, but not all threads work (the most common case);
- works periodically.
Why the rear window heating does not work: reasons how to check out the place of refusal
If the heating of the rear window stopped working, but it works, but with interruptions, this may be due to the following reasons:
1. Fault of the electrical equipment of the car.
Finding a place of failure should be started with a fuse that serves a heater. If it is working, then check the switch (button) of the heater, relay, electrical wiring to the heater contacts.
The rear window heating switch button is checked using a multimeter. Its contacts are often tightened as a result of a large current. In this case, it must be changed.
One of the most likely places of malfunction of electrical equipment - a bummer (or paying) the place of attachment of the contact terminal to the heater. Repairs in this case is difficult. It is required to produce a soldering with the help of special solders and flux. It is also possible to glue conductive paste.
Often wiring is damaged at the place of crossing the corrugations, where the wiring from the body to the door of the trunk is located. An opening of corrugations is required, wiring extraction, searching for a broken conductor and eliminating the breakdown.
2. Ombol of the filament.
Such a malfunction may be associated with the removal of a sunscreen film, mechanical scratches on glass, natural wear.
Video - How to check the rear window heating by a multimeter:
To search for a specific location of the thread break, if it is imperceptible to the eye, you must use the multimeter. Its probes should be sharpened or connected with sewing needles. It is necessary to ensure reliable contact of the probes with the heater threads. First, the method is visual or tactile (touch), the method determines the faulty thread (threads). It does not heat up. Then the resistance is measured in extreme sections of the thread.
After determining the place of damage to the thread, it must be marked with a marker.
How to fix the heating of the rear window do it yourself
To repair the rear window heating, you should purchase a special conductive glue or ready-made heater repair kits. It is necessary to carefully read the repair technology, which should be described on the packaging or the attached instructions in Russian. The success of repair work is determined by strict compliance with the technology specified in the instructions.
Video - repair threads of rear window heating with their own hands:
Overview of sets and glue for repairing threads and contacts of heating rear window
Set Permatex PX 09117
The set includes:
- adhesive for threads 1.4 ml;
- contact for contact 0.8 mm;
- tassel for applying glue;
- template;
- sandpaper;
- napkin activator;
- alcohol napkin.
Mode of application when repairing contacts:
- clean and degrease the surface;
- clean contacts;
- wipe the activator of the surface, wait 5 minutes;
- apply a small (!!!) drop of glue so that it does not make the surfaces bonded;
- press contacts;
- give a day drying.
Mode of application when repairing thread:
- degrease the surface to which the thread will be applied;
- attach pattern;
- wait 20 minutes;
- repeat the application of 3-4 times at intervals of 20 minutes;
- the heater is included in 24 hours.
The cost of such a set is about 1000 rubles.
AVS A78358S glue
Such conductive adhesive for repairing rear window heating yarns 2 ml costs about 200 rubles.
Conductive adhesive for repairing rear window heating threads.
The price of glue is about 400 rubles.
Video - How to glue the contacts of the rear window heating without removing the glass:
Repair technology is approximately the same for all industrial manufacturers. The main thing is to degrease the surface well and do not rush. If you cannot find special compounds for repair, you can try them to make them yourself or use other recovery methods.
Independent manufacture of conductive glue, soldering with special fluxes, electrolytic coating
1. Independent manufacture of conductive composition.
As the basis, the common glue BF-2 or BF-6 is often chosen. You can use other quick-drying adhesives. There are options for using a polymer resin, paint, enamel. In order to make a conductive paste from these materials, it is necessary to add a fine chips into it in a ratio of 1 to the 1st. The chips can be "mined" with a small file or supphilyla and copper, aluminum or brass material. After mixing the components, they are applied to the prepared surface through the homemade stencil. It is not difficult to make it with the help of construction tape or tape.
The effectiveness of such a self-made composition will not be worse than purchased.
2. Soldering the place of breaking thread and disconnecting the terminal.
The soldering place of the thread break is impossible if the distance between the end of the thread is more than two millimeters. In this case, you can pre-use the electrochemical method. When restoring the contacts of the connections of the heater terminals, the soldering is more efficient and reliable. The soldering is produced by a classic method using an active flux and solder. As a solder, choose POS-18 or similar. Flux is better to use a TC type based on zinc chloride.
3. Electrolytic coating.
To carry out such a coating, a solution of copper sulfate is required (the proportion is 100 milliliters of water, two teaspoons of copper sulfate, you can add a few drops of rechargeable electrolyte), rags, thread, stranded copper wire with a cross section from 6 square meters (for the manufacture of a copper bruster prototype).
Next, the copper brush from the stripped conductor wrapped with rag and thread is connected by the reverse end of the wire to the power supply of +12 volts (AKB), minus the battery is connected to the body or directly to the heater terminal. Bruster wetted in homemade electrolyte. After that, a moistened tassel is vigorously water at the site of the breaking of the thread. The processing place is gradually covered by the electrolysis process with copper particles.
The current in the car is served from the plus through the ignition lock, as well as through fuses. Then the voltage passes to the heater switch and the minus battery connects to the car body. One of the wires of glass heating system is also connected to the body.
When the driver presses the power on the system, the voltage comes on the relay. It is triggered, force contacts are closed. The current falls on the heaters, passes through the heating threads and then through the body goes to the battery.
Device of heating element
The heating element has the following device. Bocames on the rear window are conductive tires. They are attached special threads from high resistance materials. Resistance to each thread is 10 ohms.
Their number depends on the size of the glass. So, each thread is a separate element that works separately from others. All items are connected to each other in parallel. This scheme allows you to provide a high reliability system. So, if there is a break of one thread, everyone else will work.
Typical malfunctions
Before repairing the rear window heating threads with their own hands, you need to find out the fault. Depending on what kind of malfunction is manifested by externally, you can diagnose the operation of the system even without a multimeter.
It should be noted that it is possible to start glass heating only if the ignition code is enabled. On some models, the auto turn on the heating of the glass can only with the motor running. This is done in order to reduce the burden on the battery. The system for full-fledged work is necessary from 10 to 25 A current.
Heating does not turn on
So, if the system does not turn on with the corresponding button, the corresponding fuse failed. A button can also be broken. If the performance indicators are glow, but the glass does not turn off, repair the rear window heating threads are starting with checking the connectors and relays. In this case, the electrical schemes find where parts are installed and change them.
Slow spontaneity
Sometimes you can observe cases when a considerable amount of time passes between pressing the button and on the button and turning on the heating system. If over the board the low air temperature or frost, then the reason for this problem can be in bad contacts on one of the connectors. Contact resistance grows, current becomes lower, power drops.
To check this malfunction, you must use the multimeter. Change the voltage at the terminals of the heating system and battery. These voltages should not be different.
Stripes remain on the glass
This is the most popular malfunction. The problem is associated with the breakdown of the threads that are applied to the glass. This malfunction can be diagnosed by bands on the glass after the system is turned on.
The threads installed on the rear window differ in low strength. And if they have a little effect on them, it will take the repair of the rear window heating yarns.
We define the place of the cliff
It is not difficult to find a break. Near the threads, foaming or a permanent disappear. That is why it is to quickly find a damaged element, threads consider and then find a damaged place. But sometimes the cliffs are so insignificant that they are very difficult to notice. Then the voltmeter should be used.
Due to the fact that one of the tires is connected to the body machine, the minus the multimeter wire is connected to the body. Next, a positive wire with a diploma concern the first and second tires. On the first voltage is +12 B, and on the second - 0 V. If for some reason there is no access to the bus access, then the measurements can be performed where the threads come out from under the seal.
If the heating is enabled, there are 12 V in the system, but the threads do not heal, then this says that the entire wiring is before the first tire in working condition. If there is no voltage, it says about bad contact. Requires repair of threads and rear window heating contacts. Can also fail the relay.
If the voltage is not only on the first, but also on the second bus, they are looking for bad contacts in the wire connection circuit of the heat heating system.
How to find a break
Thread is a tape with a resistance of 10 ohms. In different places, the voltage will be different. In the first point, the voltage will be 12 V, in the third - 6 V, in the fifth - 0 V.. If you do not know which threads are damaged, it is easy to find it. For this measure the voltage in the middle of each strip. If the thread is trimmed, then the voltage will be either 12 V or 0. Therefore, the break from the left or right.
Repairs
There are several ways to repaired this system. The most efficient and fast is to use a set for repairing rear window heating threads.
There are many of them, they are designed to restore the integrity of the ribbons. This set is all. It is a syringe with special paste. Reviews are well characterized by the Permatex tool. Repair the rear window heating threads with it is very easy and simple. You do not need any additional tools. Everything is in the set.
So how to repair? Everything is very simple:
- With the help of alcohol or solvent we clean the glass area at the point of breaking the thread.
- We take into my hands tape and stick it on both sides of the heating element. At the same time, the distance between the ribbon should not differ from the thickness of the heating thread.
- With the help of a tassel or a syringe, we apply conductive glue or paste (depending on which set will be used). How to apply it? The glue should be overlapped by a third of the thread of 10 millimeters on each side.
- We remove the tape and wait until the glue dries. According to the instructions, the composition dries out in 24 hours.
- A day later, we remove the excess glue. This can be done with a sharp knife - kitchen or stationery. Be careful - the knife can easily damage the surface of the heating element.
- We wipe the glass soft and slightly moisturized by the rag.
- Check the performance of the element.
You can also use another means for repairing rear window heating yarns. This is "ELEKONT" of domestic production. Mass are applied to the place where the thread is torn. Apply adhesive so that it overlaps the whole part of the thread from each of the parties. After hardening, the electrical heating system will earn again.
It is believed that glue can be made self (made of metal chips). But it is not worth doing this. The finished product is much more efficient. In addition, the reliability of the technology of self-making adhesive is not confirmed.
Conclusion
So, we found out how the heating threads are arranged and how to repair them. The complexity of repair is to find a non-working tape. After all, the system will work even when half of all existing threads occurred. True, glass in this case will move half.
You will need
- - voltmeter;
- - low-headed solder and zinc chloride;
- - graphite powder, iron sawdust, nitrolac, epoxy;
- - Serious sawdust and nitroles;
- - a solution of copper sulfate, cloth, long copper wire;
- - electrically conductive glue
Instruction
Find damage to heating threads using a voltmeter. To do this, connect the device to the conductive bus to the conductive tire, and each other smoothly drive through the non-working strip. Another thread cliff search method: Turn the heating on the glass. At the same time, all the glass will quickly postpone from the place of damage. This method is easier than the previous one, but not accurate and does not always work.
Regardless of the selected repair method, pre-clean the damaged area from the varnish until the metallic shine appears. It is more convenient to make a bent wire. Decrease in any way. Having soldering skills, smear the damaged place with a soft low-key sold-18 or POS-4-6 type. As a flux, use zinc chloride. In the presence of damage on the extended site, you solder a thin copper or silver veil from a suitable piece of wire.
To restore with a different method, mark the damaged section with a mixture with a graphite powder and a small amount of epoxy adhesive (resins). So that the work turned out to be better, install a strong magnet from the back of the glass, and in the place of the recoverable area, pour small metal sawdust. They will restore the contact of the threads. After repair, damage is treated with nitroloma. Magnets are removed after full lacquer drying. When applying sawdust, try to get to the strip of the conductor as closely as possible, and not on the entire surface opposite the magnet. This will help to make a place of repair invisible.
For the third way, take silver sawdust. Prepare them, drifting the fusion of the contact of an unnecessary power relay. Sawls Pour the paper sheet into the fold and add a drop of nitroke. The end of the knife is quickly roll out from sawdust cylindrik with a diameter of 1 mm and a length of 2-3 mm. Take it on a damaged area and dispersed, tightly pressing sawdust. Surplus remove.
Another way is perfect for restoring a damaged area or all the heating thread. Prepare a solution of copper mood, consisting of 6 parts of water, two parts of powder sipop and one part of the electrolyte for AKB. Mix thoroughly. Take a thick long copper wire, reaching from a positive battery terminal to glass with threads. A piece of fabric width 1-2 cm and 10-15 cm long wound on the end of the wire and secure in any way.
Connecting another end of the wire to the positive battery terminal, moisten the wounded tissue in the cooked solution. Start vigorously rub the place of break for 1-2 minutes. At the same time, copper will be deposited around the intact thread. Copper raid will look like patterns on frosty glass. When restoring the threads, start from the location of it to the lateral transducer parts. This method is cheap, is available, differs by high durability of the restored area. On the other hand, it is quite lengthy.
To use a more modern recovery method, purchase a special electrically conductive glue. When buying consultation with the seller. To restore the thread, use the stencil included in the product. Soft tassel through stencil apply glue to a damaged area and dry 10-15 minutes.
In winter, on cars in which air conditioning works in the best way, the rear window heater is a real rescue. Driving the machine, without being able to assess the situation from the back, extremely irresponsible, and go to the flooring places with outflows on the rear window is not recommended. Some drivers to remove Failed, use the scraper, but in most car models, the rear window heater is installed capable of eliminating the problem with icing.
The rear window heater is a very simple device, which is a series of horizontal lines from electrically conductive material applied directly to the glass. Near the side faces of glass to threads are suitable vertical conductors, through which the current and enters the electrically conductive material. The simple design of the rear window heater suggests that not so much reasons can lead to its failure. Below we present the main reasons due to which the device may not work, as well as the methods of repairing the rear window heater.
One of the most common faults of this component of the car is the thread break. Thin electrically conductive threads sufficiently touching enough to take place, and this will lead to the fact that the rear window heater will cease to perform the functions assigned to it. Most often, problem zones are diagnosed visually.
If you detect visible rear window heater threads, you can use diagnostic devices for troubleshooting. Get the multimeter and use it to measure the voltage on all sections of each thread. For example, each thread takes 5 conditional control points. The negative multimeter probe is connected to the mass, and the positive is supplied to the control points of each thread. Moving the measuring probe from one end of the thread to another, the voltage drop from 12 to 0 volts should be observed on the device. If in one of the control points, the voltage is higher or below the norm, it means that this section should look at more carefully, since it has a rupture of the chain. 
Attention: Apply an acute probe to the threads of the heater should be careful not to apply new damage.
Repairs. Such a malfunction, the car enthusiast can easily be eliminated independently. A special set for restoring the rear glass heater pattern is sold in automotive stores. The kit includes stencil, conductive glue and brush. The stencil is glued on both sides of the damaged area, after which the conductive glue is applied to the problem zone. Next, it is necessary to wait until the composition dries off (about 30 minutes) and remove the stencil. 
Rear window heater fuse blocked
If any electric device on the car stopped working, first it is necessary. To the failure of the fuse can lead a temporary jump of the current in the onboard chain of a car or a more serious malfunction.
Repairs. First, try simply change the fuse and use the device in normal mode. If the problem persists, and the element again fails, determine and eliminate it.
The rear window heater can stop working properly due to the oxidation of the contact directly glued to the glass. To detect this malfunction, it is necessary to measure the supply wire voltage and make sure that it exceeds 11 volts.
Repairs. If the measurement was obtained less than 11 volts, it is necessary to clean the contact of the oxides formed. To stripping contact, you can use sandpaper paper with small grains or a special remedy removing rust.
Other faults of the rear window heater
If all the diagnostic procedures described above are carried out, but the problem is not found, it means that the heater of the rear window does not work because of the breaking of the wiring or failure of the power button. It is recommended to first deal with possible problems in the button, and if they are not detected, you will have to diagnose the wiring break.
If you are reading this article, then the heating of the rear window is definitely it is an indispensable function of your car. Nevertheless, for many decades, drivers were forced to ride without heating the rear windows. From the thermal functions of the brake of the car was only the very warm air that blends from the ventilation holes at the base of the windshield, but this, of course, it was not enough so that such air could dry and warm the rear window in the rear end of the cabin. However, if you had children, you could give them a little cloth and give orders to make the rear window to be clean, but agree, this is not a very welcome perspective!
Then this curious grid of wiring threads on the rear window appeared. The button on the dashboard includes the system, and right in front of the fog (condensate) will disappear on it. Soon such a defroster became standard for the rear windows of most cars, and today almost all the cars are equipped with the heating of the rear window.
But, unfortunately, like everything else in your car, heating is also susceptible to breakdowns. And if it happened, then the first step that should always be done in troubleshooting is a clarification, why the rear window heating does not work before proceeding to one or another more specific and thorough diagnostic or repair method.
Repair the rear window heating thread
So, the repair of the rear window heating should be started with the search for a good kit for repairing heating, which, in general, is very primitive and consists of directly conductive means (glue, varnish, etc.) and brushes for its application (sometimes included Cancellation or tape can go for the border of glue. This set is sold in almost any auto shop, and when buying should pay attention to its color - it should be yellow-red, mustard or red - most often it is precisely such means for repair are the most qualitative and Reliable. In any case, you better choose glue from those that the same color that also applied to your rear window.
The second - the price of a set of means for repairing rear window yarns should be at least 300-400 rubles - here is exactly the case when quality depends on the cost.
