With HVAC System - Automatic - RPO C68

1. If the Air Door Motor is displaced from its proper position, it will automatically calibrate itself to the proper position if the Battery power is removed from the HVAC Control Assembly. To recalibrate the Air Door Motor, disconnect then reconnect the Battery.
2. Make sure that grounds G200 and G222 are clean and tight.
3. Check CLUST Fuse. If open, check for a short to ground in CKT 750.
4. Check ELEC Fuse. If open, check for a short to ground in CKT 340.

With Engine warm and running at idle:
5. Check HVAC Fuse. If open, check for a short to ground in CKT 50.
6. Check manifold vacuum at the black hose from the Engine to the Vacuum Tank.
7. Check for vacuum at the vacuum hose from the Vacuum Tank to the Solenoid Box.
8. Check that the vacuum hoses from the Solenoid Box to the Vacuum Actuators are connected and in good condition.
9. If Rear Defogger does not operate properly or is inoperative, refer to "Rear Defogger,"
10. If Steering Wheel Control functions do not operate, but HVAC Control Assembly functions properly, refer to "Steering Wheel Controls (UK3)."

^ Check for a broken (or partially broken) wire inside of the insulation which could cause system failure but prove "GOOD" in a continuity/voltage check.
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.