Minor damage to the wires can be repaired by yourself.
Examination
1. Turn on the ignition and heater. Connect a voltmeter between the heater leads. If there is no voltage, then check the fuse, switch and wires.
2. Put a folded strip of aluminum foil on the voltmeter probe and press your finger against the heater thread in the center.
3. If the voltage is 6V, then the thread is good, the voltage is 12V, then the thread is broken (break occurs between the center of the thread and the mass). If the voltage is 0 V, then the thread is broken between the center and the supply terminal of the heater.
4. If the threads are good, then connect (-) - heater output with ground. If the voltmeter reading changes, the ground connection is poor.
5. The place of a broken thread can be established by leading the aluminum contact on the voltmeter probe along the thread away from () - output to (-) - heater output. Connect the voltmeter to (-) -conclusion. At the break point, the voltmeter reading should drop sharply.
Repair
1. Splice broken heater filament with Dupont N 4817 conductive epoxy or equivalent.
2. Turn off the heater.
3. Carefully polish the damaged area with a steel sponge and wipe with alcohol.
4. Apply a mask of adhesive tape to the damaged area.
5. Prepare the resin according to the instructions.
6. Apply the composition to the gap in the mask, smearing approximately 18 mm in both directions.
7. Remove the mask after 24 hours.