With Manual A/C

1. Check IGN Fuse. If open, check CKT 250, CKT 459 and CKT 59 for a short to ground.
2. Check that grounds G103 and G108 are clean and tight.
3. Check A/C Compressor Clutch Connector terminals for corrosion.
^ 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.