Troubleshooting Hints - Compressor Controls

1. CHECK the condition of the HTR-AC Fuse 12, ECM-B Fuse, A/C Fuse, and IGN-E Fuse. If any fuse is open, then LOCATE and REPAIR the cause of the overload and REPLACE the fuse(s).
2. If the HTR-A/C Fuse opens every time that the Heater and A/C Controller is placed only in the MAX A/C, A/C, Bi-Level, Blend, or Defrost positions, then REPLACE the Heater and A/C Controller.
3. CHECK that Grounds G101, G103, and G201 are clean and tight.
4. CHECK that the A/C Compressor Enable Relay is properly seated in its socket.
5. CHECK the condition of Diode D102 at the Underhood Fuse-Relay Center. REPLACE Diode D102 if it is either open or shorted.
6. If the A/C Compressor Clutch does not cycle on and off during normal operations, then check the A/C Compressor Low Pressure Cutout Switch for failure.
^ CHECK for a broken (or partially broken) wire inside 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