Tests AM

PINPOINT TEST AM: THE DEFROST SYSTEM IS INOPERATIVE

Test AM1-AM2:

Test AM2-AM5:

Test AM5-AM7:

Test AM7-AM10:

Test AM10-AM12:

Test AM12-AM13:

Test AM14-AM16:

Normal Operation
12 volts are supplied to the BEC rear window defrost relay from the BEC fuse 13 (40A). Once the rear window defrost relay is energized by the SJB, 12 volts are supplied to the rear window defrost grid on circuit 186 (BN/LB). The rear window defrost switch supplies a request signal on circuit 1426 (PK) to the SJB. When the request is received, the SJB energizes the rear window defrost relay by supplying 12 volts on circuit 298 (VT/OG) and controlling the ground on circuit 1389 (WH). The rear window defrost grid is grounded though circuit 1205 (BK).

Possible Causes
- circuit 1389 (WH) open or short to voltage
- circuit 186 (BN/LB) open
- circuit 1205 (BK) open
- circuit 1426 (PK) open or short to voltage
- circuit 298 (VT/OG) open
- rear window defrost relay
- BEC
- SJB
- rear window defrost grid