96 Silverado Z71 no AC

[OldGuy96]

I'm working through a series of electrical issues with this truck, none of which have (so far) been major. I'm hoping that someone can give me some guidance on the AC not working.

The blower runs on all three speeds, I can adjust the heat to warmer of cooler, and the floor, dash and defrost modes seem to work fine. The problem is that I don't have any lights on either the AC or Recirculation switches on the climate control module. I had lights at one time, but the compressor hasn't run since I've owned the truck.

I'm not educated on how the AC should work on this truck, what the power flow is to activate the compressor, or what the common problems with the AC are. Any help to troubleshoot this and get the AC working as it should would be much appreciated!

[brcidd]

Put a guage on a/c you need pressure to activate it- at least 47 psi- mostcommon failure is loss of refrigerant due to a belly leaker compressor.

[j cAT]

Originally Posted by OldGuy96

I'm working through a series of electrical issues with this truck, none of which have (so far) been major. I'm hoping that someone can give me some guidance on the AC not working.

The blower runs on all three speeds, I can adjust the heat to warmer of cooler, and the floor, dash and defrost modes seem to work fine. The problem is that I don't have any lights on either the AC or Recirculation switches on the climate control module. I had lights at one time, but the compressor hasn't run since I've owned the truck.

I'm not educated on how the AC should work on this truck, what the power flow is to activate the compressor, or what the common problems with the AC are. Any help to troubleshoot this and get the AC working as it should would be much appreciated!

being this old the ac system will need a pressure check. if your system is low on refrigerant the compressor will not work. reason is if it does with not much refrigerant the compressor will lock up.

on the refrigerant tank passenger side is a switch. this is what stops the compressor from working when the refrigerant is too low like less than 5-10 psi. this is called the low pressure cutout switch. this is used in most all ac systems to prevent compressor damage. I would have an ac person see if it is empty , find the leak, and if you have some money fix it.. if compressor is the leak issue get a scrap yard one cheap..

[OldGuy96]

I'll check on the compressor leak. I understand that the compressors on this model tend to leak around the middle joint.

Do compressors from newer models fit this system, and if so, what years should I be looking for?

[j cAT]

Originally Posted by OldGuy96

I'll check on the compressor leak. I understand that the compressors on this model tend to leak around the middle joint.

Do compressors from newer models fit this system, and if so, what years should I be looking for?

If the compressor body has an oil on it the compressor is leaking. replacing the compressor with the same type is required. system designed for this and the mounting. this is a very well used compressor and it is not the same as the new vehicles use.

GM mounted the ac compressor at the low point of the ac system this causes compressor failures ..when the compressors where mounted up high these lasted for decades with no problems...

what testing has been done ?

[Tech II]

First, get gauges on this to see the pressure.....should equal ambient air on a cold engine....ambient air 80F, the lo=hi pressure with system of should be 80 psi.....

If pressure is ok, turn ac on, remove two wire connector from switch on accumulator, and jumper the harness to see if the compressor comes on....