Test G: The Defrost System Will Not Shut Off Automatically

PINPOINT TEST G: THE DEFROST SYSTEM WILL NOT SHUT OFF AUTOMATICALLY

G1-G3:

G3-G5:

G6:

Normal Operation
The BEC fuse 13 (40A) supplies 12 volts to the BEC rear window defrost relay. 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 186 (BN/LB) short to voltage
- Circuit 1389 (WH) short to ground
- Circuit 1426 (PK) short to ground
- Rear window defrost relay
- SJB