Ok,started acting up a week ago,kick in and then shut off.This the wrong summer for this stuff....
I checked the charge ,right up to snuff.
I checked power at the clutch with switch in various ac posistions and no power.
I put 12v to the green with and compressor kick in and ran fine.
I pulled dash switch disassembled ,clean and reassembled all is fine there.I have 12v coming out of the switch (green wire) for ac.Yet no voltage at green on comp clutch?
Would a bad low pres switch be the issue?
Any other ideas?
Thanks...

Upon further reading of post's(difficult on phone,lol) seems I have the high and low cut offs to check and then the relay,center relay on firewall above accumulator.
If you think of any thing else please send a heads up..
198,000 miles and still going.

 

The charge must be read with the compressor running...

 

I had the same problem with mine a few weeks back, it would cut on for a few seconds then shut off, it had a full charge of freon. Mine ended up needing a cycling switch which is located on the accumulator on my 95. It just unscrews off and it has a valve behind it so it does not loose freon when you remove it. It was a $15.00 part at NAPA.

 

How does one check the cycle switch?
I did check the freon when I could manage to keep the compressor kicked in,before it stopped alltogether.My gauges are only color coded but it was smack in the green(good) zone.
My haynes manuals dont get into the ac all that much...
Thanks...

 

The way I found out was not very technical...I took a screwdriver and tapped the switch pretty hard and the clutch on the compressor engaged. It is only 2 wires so you can unplug it and run a jumper wire between the two and your clutch should engage.

 

To jumper the switches, unplug the connector and put a wire or paperclip between the two contacts on the connector (be careful not to bend the socket contacts).

If wiggling the wires does anything, unplug that switch and check the connector contacts.

My A/C cut out the other week because of a loose connection. I had a 2/0 power wire for my stereo that was pushing against the low pressure connector because of the way I had it run off the alternator. The socket contacts got bent out over time so one of the wires stopped making contact with the switch pins. I fixed my A/C with a pocket knife that morning...


If jumpering your L/P switch kicks on your compressor but it won't run when you plug it in, the pressure is probably too low or the switch could be faulty (you really need to have a tech check with proper gauges to find out for sure).

If jumpering the H/P switch on the compressor kicks it on, the H/P switch could be your problem. You'd need an A/C tech to discharge the system, replace the switch, and do a re-charge.

 

As soon as it stops raining I'll go jump some switches...
The AC kicked on again for about ten minutes on the ride home...
The connectors all appear in good shape and making contact..
With any luck I'll get off cheap on this one...Hard to justify putting to much money into a15 year old BLAZER with 198,000miles on it with New England rust.
Thanks again.

 

I found the problem,it is the switch on the accumulator,jumped it out and cool/cold as it ever was....
What is the official name of that switch? I will have to run to Napa after work and grab one anyways.
Thanks for all the help and insight.

 

It is called a cycling switch, glad it worked out for you.

 

Cycling switch or low pressure cut-off switch.