General

1. Refer to HVAC Air Delivery And Temperature Control for diagnosis of Ventilation System controls.
2. Refer to HVAC Compressor Control for diagnosis of Compressor Controls.
3. Refer to Defogger for diagnosis of the Rear Window Defogger Controls. Heated Glass Element
4. Refer to Instrument Panel Dimming for diagnosis of the Instrument Panel Dimming System. Lighting and Horns
5. CHECK for broken (or partially broken) wire inside of 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).
6. CHECK for proper installation of aftermarket electronic equipment which may affect the integrity of other systems. Refer to "General Troubleshooting Procedures,". Diagnostic Aids