Note:
- - When cleaning the glass, use a soft, dry cloth, wipe the glass parallel to the heater wires.
- - Try not to damage the wires. Do not use detergents or compounds with abrasive particles.
- - When measuring voltage, wrap the negative terminal of the tester with foil and press the edge of the foil to the wire with your finger.
Checking the rear window defroster switch
1. Checking for broken wires.
a) Turn on the ignition and rear window heater.
b) Measure the voltage at the center of each thermocouple wire as shown in the figure.
c) If the voltage is about 5V, then the wire is normal.
d) If the voltage is about 10 V, then there is a break in the wire between the middle and the side bus (+) of the thermoelement.
d) If the voltage is about 0 V, then there is a break in the wire between the middle and the ground.
2. Finding the location of the break in the wire.
a) Connect the positive terminal of the voltmeter to the side bus (+) of the thermocouple.
[The material was taken from a resource: Toyotaman.ru]
b) Wrap the "minus" of the voltmeter with foil. Connect the foil to the thermocouple wire at the side bus (+) and slowly move it to the opposite end (to "ground"),
c) The point at which the voltmeter needle deviates from zero by several volts is the break point.
Note: If there is no wire break, the voltmeter shows 0 V at the side bus (+) of the thermoelement and, when moving the "-" contact of the voltmeter to the opposite end of the wire, the voltage will gradually increase to approximately 12 V.
3. Repair of wires.
a) Clean the ends of the wire at the break point with solvent and stick protective tape on both sides of the wire.
b) Mix the repair compound thoroughly and apply a drop of the substance to the wire using a fine-tipped brush.
Repair compound: DUPONT PASTE No.4817 or similar substance.
c) After a few minutes, remove the protective tape and leave to harden for 24 hours.