Repair of the rear window heating threads by one's own hands: step by step instruction, device and feedback

The current in the car is supplied from the positive terminal of the battery via the ignition switch, and also through the fuses. Then the voltage goes to the heater switch and to the relay contact. The minus battery is connected to the car body. One of the wires of the glass heating system is also connected to the body.

When the driver presses the power button, the voltage comes to the relay. It is activated, the power contacts are closed. The current gets to the heaters, passes through the heating filaments and then through the body goes to the battery.

The device of a heating element

The heating element has the following device. On the sides on the rear window there are conductive busbars. To them are attached special strands made of materials with high resistance. The resistance of each filament is 10 ohms. The number of them depends on the size of the glass. So, each thread is a separate element that works separately from the others. All elements are connected to each other in parallel. This scheme allows the system to provide high reliability. So, if one thread breaks, all the others will work.

Typical malfunctions

Before repairing the rear heating filaments with your own hands, you need to find out the faults. Depending on which fault appears externally, it is possible to diagnose the operation of the system even without a multimeter. It should be noted that it is possible to start the heating of the glass only if the ignition is switched on. On some car models, it is only possible to turn on the glass heating when the engine is running. This is done in order to reduce the load on the battery. A system for full operation requires 10 to 25 A of current.

Heating does not turn on

So, if the system does not turn on from the corresponding button, the corresponding fuse may have failed. A button may also be broken. If the operation indicators glow, but the glass does not sweat, repair of the rear window heating wires should start with checking the connectors and relays. In this case, according to the electrical diagrams, they find where the parts are installed and change them.

Slow sweating

Sometimes it is possible to observe cases when a considerable amount of time passes between pressing the button and turning on the heating system to sweat the glass. If there is a low air temperature or frost overboard, the cause of this problem can be in bad contacts on one of the connectors. The resistance on the contact increases, the current becomes lower, the power falls. To check this fault, use the multimeter. Change the voltage at the terminals of the heating system and the battery. These voltages should not be different.

On the glass there are strips

This is the most popular fault. The problem is related to the breakage of filaments that are deposited on the glass. This fault can be diagnosed by strips on the glass after the system is switched on.

The threads installed on the rear window are of low strength. And if they have at least a little impact mechanically, then you need repairing the filaments of heating the rear window.

Determine the place of precipice

Find a cliff is not difficult. Near the thread, the fog or the frost will not be lost. That is why, in order to quickly find the damaged element, the threads are counted and then find the damaged space. But sometimes the precipices are so insignificant that it is very difficult to notice them. Then you should use a voltmeter.

Due to the fact that one of the tires is connected to the body of the car, the minus lead of the multimeter is connected to the body. Next, the positive wire with the probe touch the first and second bus. On the first voltage is +12 V, and on the second - 0 V. If for some reason there is no access to the buses, measurements can be made where the threads come out from under the seal. If the heating is on, there is 12 V in the system, but the threads do not heat, this means that all the wiring before the first bus is in working order. If there is no voltage, this indicates a poor contact. It is necessary to repair the threads and contacts of the rear window heating. The relay may also be damaged.

If the voltage is not only on the first, but also on the second bus, then they look for bad contacts in the connection of the wires of the heating system to the mass.

How to find an abrupt

A thread is a tape with a resistance of 10 ohms. In different places, the voltage will be different. In the first point, the voltage is 12 V, in the third - 6 V, in the fifth - 0 V. If you do not know which of the threads is damaged, it is easy to find. To do this, measure the tension in the middle of each strip. If the thread is broken, then the voltage will be either 12V or 0. Consequently, the break is left or right.

Repairs

There are several ways to repair this system. The most effective and fastest is to use a set for repairing the filaments of heating the rear window. They are many, they are designed to restore the integrity of the tapes. In this set there is everything. It is a syringe with a special paste. The reviews well characterize the means of Permatex. Repair of the heating filaments of the rear window with it is very easy and simple. You do not need any additional tools. Everything is in the set.

So, how to make repairs? Everything is very simple:

• Using alcohol or solvent, we clean the glass area at the point where the filament breaks.
• We take in the hands of adhesive tape and paste it on both sides of the heating element. In this case, the distance between the belt should not differ from the thickness of the heating wire.
• Using a brush or a syringe, apply a conductive glue or paste (depending on which kit will be used). How to apply it? The glue should cover a whole part of the thread 10 millimeters on each side.
• Remove the adhesive tape and wait until the glue dries. According to the instructions, the composition dries in 24 hours.
• After a day, remove excess glue. This can be done with a sharp knife - kitchen or clerical. Be careful - the knife can easily damage the surface of the heating element.
• Wipe the glass with a soft and slightly moistened rag.
• We check the operability of the element.

Also, you can use another tool to repair the rear screen heating filaments. This "Elecont" domestic production. Mass is applied to the place where the thread is broken. Apply the glue so that it covers the whole part of the thread from each side. After curing, the electric heating system will again work. There is an opinion that glue can be made by yourself (from metal shavings). But do not do this. The finished product is much more effective. In addition, the reliability of the technology of self-made glue is not confirmed.

Conclusion

So, we found out how the heating threads are arranged and how to repair them. The difficulty of repairing is finding a broken tape. After all, the system will work even when there was a break in half of all available threads. True, the glass in this case will fog up half.