With Electronic Controls

1. Check for an open in Fuse 15. If open, repair short to ground in CKT 541.
2. Check for an open in Fuse 10. If open, repair short to ground in CKT 640.
3. Check for an open in Fuse 14. If open, repair short to ground in CKT 40.
4. Check for corrosion on connector terminals at Blower Motor and Blower Motor Control Module.
5. Make sure ground G203 is clean and tight.
6. If Blower Motor can be controlled in either the "Manual" mode or the "AUTO" mode but not in both, replace the Heater-A/C Control.
7. Check if any trouble codes are set by observing if the C or the F is flashing during the first 2 minutes of operation. If codes are set, refer to the diagnosis in HVAC AIR Delivery and Temperature Control (CJ2).
8. If the steering wheel control functions do not operate but the Heater-A/C Control functions operate properly, refer to Steering Wheel Controls. Testing and Inspection
9. If Blower runs with the Heater-A/C Control "OFF" check CKT 65 for a short to Battery.
^ 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.