Without Electronic Controls

1. If the Heater-A/C Control is completely inoperative, check for poor connections at Heater-A/C Control Connector C1.
2. Check for missing or damaged connector seals at the Blower Motor Resistor and Blower Motor Relay.
3. Check Fuse 4 if the Blower Motor is inoperative. If open, check for short to ground though CKT 41.
^ 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.