Component Tests and General Diagnostics
PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS:1. Check RR Defog Fuse and the HVAC Fuse.
2. Refer to repair procedures If one or more of the grid lines do not heat.
3. If the Panel Light is inoperable with the Headlight Switch in "PARK" or "HEAD," check bulb and wiring to bulb (CKT 8 - Power, CKT 150 - Ground).
^ Check for a broken (or partially broken) wire inside of the insulation which could cause system failure but prove "GOOD" in a continuity/voltage check (refer to "General Troubleshooting Procedures,"). Diagnostic Aids
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems (refer to "General Troubleshooting Procedures,").