Rear Window Defogger System Does Not Operate

CIRCUIT DESCRIPTION
The signal via the rear defogger switch is transmitted to the luggage room J/B from the air conditioning amplifier. Then the luggage room J/B outputs it to the defogger relay.

NOTE: The rear window defogger system has a function with large-scale body multiplex communication. First of all, inspect the communication function according to "How To Proceed With Troubleshooting", and check that no malfunction exists in the communication system. Then proceed with the troubleshooting.

Wiring Diagram:

Step 1:

Step 2 - 4:

Step 5 - 7:

Step 8:

INSPECTION PROCEDURE