1995 Chevrolet PU Truck AC Problem

[jowens1997]

Hi.
For no apparent reason, my AC compressor clutch suddenly does not engage. All fuses check ok. I have NOT checked out the relay. With controls set and engine running, no power is coming to the clutch. I have jumped across the low pressure switch and still nothing. To assure that it is a control or relay problem, I would like to temporarily run a hot wire straight from the battery to 1 of the 2 wires that activate the compressor clutch but I'm not sure which 1.
Any help is appreciated. Also, how do I check out the relay ?
I'm new to the Forum. I'm also limited on AC repair but I do have a professional set of gages and re-charge my systems.
Thanks Bob
jowens1997@aol.com

[Brian_UK]

I don't know your vehicle but the electrical circuit is often the same regardless of make (I hope!).

The power to the clutch is usually fed through a separate fuse from the a/c controls, it would normally go through a power relay after the fuse and then to the clutch.

You should be able to find a connector of some sort in the power feed to the clutch but if not then I suppose you will have to break into the wires.

Being 12vdc means one wire will be (+) positive and the other will be (-) negative. If you break the wires a meter might show you which wire in 'down to earth' or back to the battery (-) assuming a negative earth vehicle.

If you cut both wires then it doesn't matter which is which if you are going to jump it straight from the battery using two wires (+) & (-).

Hope this is of some help..

[northern-tech]

Hi Brian,
My truck acted up last year too. I thought it was low on *****, so I removed the R - 12, and put in R414 - B. However, at the point, I could not get the compressor clutch to pull in, no matter what.....unless I jumped 12 directly from the battery. Bypassing the low pressure switch did nothing. I would get AC flashing on the display....thats it. I then read, on another forum, that if a fault occurs in the system, the only way to clear it, is to remove power for a bit. I disconnected the battery for a minute, reconnected, and the AC has worked perfect ever since.
I think if you remove the plug that pushes on the compressor, and put 12V +, on one of the terminals, it should pull in the compressor.

[Karl Hofmann]

For more indepth help, you could try
The Arizona Air forum The guys on there are very good on US automotive aircon

[jowens1997]

Thanks for all the help.
Bob