Initial Inspection and Diagnostic Overview

1. Check for an open A/C PROG Fuse or A/C Clutch Fuse.
2. Check for corrosion on connector terminals at Blower Motor and Blower Power Module.
3. Check for an open A/C Blower Fuse at Underhood Fuse Block #1.
4. Make sure grounds G106 (VIN J) or G109 (VIN P) are clean and tight.
5. If Blower Motor runs at high speed or runs when the Heater and A/C Control Head blower mode is "OFF," check for an open A/C MDL Fuse.

^ 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.
^ If the Heater and A/C Control Head and/or Programmer appear completely inoperative, refer to A/C System Check and perform Chart #2 before proceeding.