A/C troubleshooting question

[AZ Alan]

I have a 1991 Cherokee that I recently purchased. When I bought it the A/C and heat worked fine. After power washing the engine area the a/c and blower no longer work. The fan clutch does not engage and the blower does not work for heat or cooling. I have checked the fuse and have checked the blower motor, both are OK. Can anyone direct me to a step by step troubleshooting guide for a/c issues? I have a feeling it is a bag switch or relay but do not know where to begin or how to test.

Alan

[AlohaBra]

Wiring diagrams are here:

http://www.autozone.com/servlet/UiBr...3d80153e8f.jsp

Do you have a Digital Multi-meter?

Tip: use our search feature or the web search engines.

[AZ Alan]

I have this wiring diagram in a repair manual. It does not show the location of any relays or switches for the A/C system.

I do have an older analog multi-meter. I do not have a digital meter.

Alan

[AlohaBra]

The fan clutch is mechanical and should be replaced if not working.
The fuse for the heater control is in the fuse box on the RH pillar area.
The fan control unit has been known to go bad.

Any voltmeter will work in this case. The digital is more for electronics.

All the swiches and relays are under the hood.
Pressure switches are on the hoses.
Temp sensor for the fan is in the radiator.
Relays are in the PDC.

See if this will help:
93 MY
http://www.dua1.com/AdminFiles/Jeep/...%26_relays.pdf