Hi Guys,
I have a problem with the air conditioning in my 95 GMC Sierra p-up. The truck is a 5.0, 1500 with 2/wd.
Anyway, a couple weeks ago the ac would work when it wanted too, which is not too often now. I see no traces of ac oil on any of the fittings/lines.
I am wondering if this has some type of ac relay & where on the ac system will I find it? I see a few different parts on the ac system that have some sort of sensor or relay??? So, I am not too sure which one to replace, or if replacing them would solve the problem at all.

I am thinking that it hasn't lost the ac charge, because when it does work it is ice cold, & because I see no trace of ac oil either.

Thanks in advance

 

If the compressor isn't operating during the failure try jumping the switch on the accumulator.

 

Thanks for the reply Davo, but could I ask you how to do that? Once I know how to jump it, what should I expect to see & what next? replace the one on the accumilator or the compressor?

If you or anyone else can explain this in step by step instructions, I would greatly appreciate it.

Thanks

 

next time the a/c fails to work, by disconnecting the switch on the accumulator and using a jumper such as a paperclip and jumpering the two pins together on the connector you just disconected, if the compressor then runs you will know you either have a bad switch or the system is low on freon.
you might also check for power and ground at the compressor clutch using a voltmeter as they can fail and commonly work intermitantly if you have 12 volts power and ground and the compressor is not kicking in then the clutch field coil is bad.

 

Let me add that these are only tests these guys are referring to. Do not leave any jumpers in place permanantly or you'll do damage.

 

Thanks bejay for the explaination on how to test this, & what to look for. I was able to test this yesterday, & today I went to the dealership to get the ac pressure switch & it is ice cold once again thanks to you!

Thanks again for your time in providing such great & easy detail, & for saving me some $$$ too!

Thanks to Desi501 as well for your help & very good advice.