97 Tahoe LT 4x4 AC Problem (Compressor not turning on)

[Ballaholyk84]

Hows it going everyone? So its starting to warm up here in Oregon and time to use my AC. Went to turn it on and realized its not producing cold air.

I get home this evening, check pressure in Low Pressure side and reading at ~45lbs (normal for the ambient temp) which I verified isnt low. I notice the compressor is not kicking on. I jump the relay and it kicks on no problem. Swap out the relay with another good one, no go. I havent dove into the AC too much in the past but I do notice now that the Low pressure line from valve to Condenser gets nice and cold when the compressor is on. The line running into the cab gets nice and cold. Small line from bottom is nice and cold. Line to high pressure side is nice and HOT. Is this normal? I never noticed it before but all lines and condenser are nice and cold (cold enough to build up condensation) except that one on the High Pressure side.

Look like there are only two switches on the system as well. The One at the Condenser and the other right behind the High Pressure Side. Could it be possible that one of those have gone bad? If so, how would I go about testing them to see if its the switch or the actual plug?

Any help would be greatly appreciated. Thank you.

 

[drakon543]

It may sound stupid and redneck but i incidentally diagnosed the a/c on my suburban by hitting those switches. Same symptoms as you and not wanting to pay the shop 150 bucks for thier quote to diagnose and fix my problem. I started checking everything out got frustrated and gave the tank a quick rap in frustration and bam it poped on. Got it to stop functioning again and i gave the sensor on the tank a quick tap and sure enough it poped on again. Anyway it turned out the switch was just sticking so i replaced it and never had a problem again. Im sure there is a legitimate way to check those maybe jumping the connection at those switchs. If it kicks on its probably that one.

 

[Ballaholyk84]

Well unfortunately before you responded to that I was going over everything again. The switch on the high pressure sign looked to possibly be a replacement one from the previous owner(s) and it looked backed off slightly. Grabbed a wrench just to make sure it was tight and just as it barely moved, the entire switch and nipple broke off clean like it was super brittle and ready to go. Unreal. Talk about a ****** thing happening when you have a system full of Refrigerant. Super lame! Now I guess I am going to track down new hoses and crap.