Test F: The Defrost System Is Inoperative
PINPOINT TEST F: THE DEFROST SYSTEM IS INOPERATIVEF1:
F2-F5:
F5-F7:
F8-F10:
F10-F12:
F13:
Normal Operation
The rear window defrost relay receives power from the battery junction box (BJB) fuse 23 (40A) on circuit 185 (BK). When the rear window defrost switch is pressed to the ON position, a ground is supplied to the smart junction box (SJB) on circuit 1010 (DB/OG), through the rear window defrost switch, then through circuit 570 (BK/WH). Upon receipt of the ground, the SJB activates the rear window defrost relay, which then supplies 12 volts to the rear window defrost grid on circuit 186 (BN/LB) and circuit 186 (BK). The rear window defrost grid is grounded through circuit 57 (BK).
Possible Causes
- Fuse
- Circuit 57 (BK) open
- Circuit 185 (BK) open
- Circuit 186 (BN/LB)/circuit 186 (BK) open
- Circuit 570 (BK/WH) open
- Circuit 1010 (DB/OG) open or short to ground
- Rear window defrost relay
- Rear window defrost switch
- Rear window defrost grid
- SJB