Troubleshooting Hints - General

1. Refer to Instrument Panel Dimming for diagnosis of the Instrument Panel Dimming Lamp circuits. Lighting and Horns
2. If the Mode or Temperature Doors do not operate smoothly in response to control dial changes, the rheostat in the module may be bad or a ground connection from the module may he open.
- CHECK for a broken (or partially broken) wire inside 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