Fan Clutch A/C Question

[TangTonic]

Hey Guys,

I have been without a/c for awhile and finally decided to do something about it. Here's what I know- the fan clutch is not spinning. I can spin it by hand with the truck off. With the a/c on max, voltage gets to the fan clutch terminal when the low pressure switched is jumpered. When the terminal is not jumpered- no voltage. Even with voltage- the fan clutch doesn't spin and a/c blows hot.

So I assume I either have pressure issues or a faulty low pressure switch for one. That doesn't solve the fan clutch problem. Do I need a new fan clutch to get a/c? I don't have overheating issues. Do I just need a shim? Or is my compressor bad? What is the next step in troubleshooting?

Thanks for the help.

 

[justinray]

The switch is wired to a lot of different sensors.. If there is a lack of freon, no engagement, too hot, no engagement, wide open throttle, no engagement.. Im not sure what else, but the whole thing doesnt work if there is one bare wire, or a bad sensor, or low charge.

 

[OLDBULL8]

Well in the first place there is no connection between the AC clutch and the engine fan clutch.
With the engine running and you jumpered out the AC pressure switch and the AC clutch engages then you have very little or no refrigerant in the AC system, wether it be R12 or 134A or the like. You need to charge it, a 93 more than likely has 134A in it. 134A is readily available at any auto store and many other places. There should be a lable on the front of the truck indicating what you have, and how much to charge it. If the lable says 134A, get a three cans of it and a charging hose with the gage on it. If it's R12 then you would have to change over to 134A. Tell us what you have.

The engine fan clutch is free wheeling, you can spin it with engine off and it should have a slight drag, it doesn't fully engage until the air temp from the radiator reaches 220 degrees. There is no electrical of any kind to the engine fan.

 

[justinray]

I presumed he meant ac clutch.

 

[franklin2]

If you have voltage to the compressor clutch but it won't kick in, the clutch gap may be too wide. There is a upper limit, I think it's around .030. Take some feeler gauges and check the gap with the engine off.

There is also the possibility the coil is burnt out in the clutch.