Component Tests and General Diagnostics

1. If the rear defogger and the outside rearview mirrors are inoperative check the REAR DEFOG circuit breaker and the HVAC Fuse for an open.
^ If the HVAC Fuse is open, check circuit 41 for a short to ground.
^ If the REAR DEFOG circuit breaker is open, check circuit 1040 for a short to ground.
2. If the rear defogger is inoperative check and make sure that G200 and G401 are clean and tight.
3. Check rear defogger grid for opens. Refer to Windows for procedures. Testing and Inspection
4. If the outside rearview mirrors are inoperative, check the HEATED MIRROR Fuse for an open. If the HEATED MIRROR Fuse is open, check circuit 267 for a short to ground.
5. If the outside rearview mirrors are inoperative, check and make sure G301 is clean and tight.
^ Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove GOOD in a continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should be checked by monitoring for a voltage drop with the system operational (under load).
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems. Refer to General Troubleshooting Procedures. Diagnostic Aids
^ Refer to System Diagnosis.