aircondition pump
1. There is insufficient freon in the system. If this is the case, not enough pressure will be in the system to open and close the pressure switch which is used to engage and disengage the clutch. To protect the system, a pressure switch is used which will prevent the clutch from engaging if low on freon. I can't recall if there are two pressure switches but you can find this out from a schematic. If you don't have one, I have the schematics for '91 and '95, at least one of which should be similar if not identical
2. The clutch coil is bad. A simple conitinuity test might tell you if this is the case, only if the coil is failed open or if you know what the resistance should be. I assume you could also apply 12V to the coil to see if the clutch engages (if you do this, do it with the engine off for safety reasons).
3. The pressure switch(es) in the system has failed.
4. Power is not getting to the coil.
5. Wiring problem.
How easy it is to fix depends on what the problem is. Many times the problem is low freon, which means there's a leak that also needs to be fixed.




