I can't seem to find what controls my AC pump, the two wires connected to the AC pump auctuating the clutch is dead. I was able to get my AC working by running a couple wires to the pump and putting them on a toggle switch for now but I want to get it working the way it's suppost too.

My Chiltons repair manual won't tell me much about the AC unit.

Where do the two wires head to from my AC pump, are they controlled by the dash assembly? or do they run thru a fuse box?


Just wondering if I need to buy a whole new switch assembly in my dash

 

I think the first thing that you should check is the low pressure switch. On top of the accumulator? there is a wiring connection to a sensor. take it off and jumper across the contacts to see whether the clutch engages.

These sensor/switches go out often.

 

I'm not sure which switch your talking about or what exactly the accumulator looks like. I suspect its the big aluminum can? I have one sensor but it's in line and not on the can looking thing. I'll give it a go, just don't wanna go pulling on something and have all my gas leak out

 

The accumulator is usually "the big aluminum can" that you are talking about, and like smokee stated, it contains a pressure switch to keep your compressor from running in the event there is not enough freon in the system. Since the freon also contains your oil for the compressor, low freon----low oil----toast goes the compressor.

By jumping the low pressure switch you bypass the switch and tell the compressor to come on.......just make sure that you have the proper amount of refrigerant in the system b4 you let the compressor run for any length of time.

 

Drier/Accumulator on my 99. The green plug is the low pressure switch.



Chris

 

When I bought my 95 it had a toggle switch to run the AC. I took the dash apart and found that the Heater/AC controller disks were not touching. I cleaned the contact points, put it back together and it works great.

 

The compressor clutch power comes from a realy in the power distribution center. The control side of the circuit has several things that have to be in agreement for the relay to activate. The dash controls have to be in the ac position or defrost. The high and low pressure switches have to be in the correct state, and the pcm has to agree to activate the clutch. I would start with fuses and relays, for a 2000 the fuse is #11 10A yours may be different. If the truck has alot of use on the dash switch I would look closely at that. If you can't find anything electrical, then you need to check your referidgerent levels.