Normal Operation
WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Under normal operation, the heated rear window relay receives power from circuit 1113 (YE/LG) and central junction box (CJB) fuse 10 (10A). When the rear window defrost switch is depressed on the HVAC module, a signal is sent to the instrument cluster (IC) through circuit 1010 (DB/OG). Once the IC receives the signal to turn on the rear window defrost, the IC grounds circuit 1009 (OG/YE) to activate the heated rear window relay. Power is then sent to the rear window defrost grid through circuit 186 (BN/LB) from the heated rear window relay. The rear window defrost grid then receives ground through circuit 57 (BK) to chassis ground.
- DTC B1345 Heated Backlite Input Circuit Short To Ground - Heated backlite switch input short to ground
This pinpoint test is intended to diagnose the following:
- Heated rear window relay
- Wiring, terminals or connectors
- HVAC module
- IC