Pinpoint Test 6

PINPOINT TEST 6: THE DEFROST SYSTEM IS INOPERATIVE

Step 1 - 6:

Step 7 - 11:

Step 12 - 13:

Normal Operation
The rear window defrost relay receives power from the BJB fuse 23 (40 A) on circuit (B). When the rear window defrost switch is pressed to the ON position, a ground is supplied to the SJB on circuit (DL/O), through the rear window defrost switch, then through circuit (B/W). Then the SJB activates the rear window defrost relay. The rear window defrost relay then supplies 12 volts to the rear window defrost grid on circuit (BR/LB). The rear window defrost grid is grounded through circuit (B) to ground.

Possible Causes
- circuit (B) open
- circuit (B) open
- circuit (BR/LB) open
- circuit (B/W) open
- circuit (DL/O) open or short to ground
- rear window defrost relay
- rear window defrost switch
- rear window defrost grid
- SJB