Hot A/C

[jbsmithsa]

I have a 1996 Suburban and the front A/C blows hot. I have checked it and it shows to be fully charged. When I take the black screw on cap off the high side refrigerant line air or refrigerant, I can't tell what it is, spews out as if the stem is not sealing. Can anyone give me an idea of what to check or what may be the problem. I am concerned about taking it to a repair shop without at least having some idea of what the problem may because I don't want them to just start changing parts or tell me the whole a/c system needs to be replaced.

Thanks in advance for your input.

[nm156]

Hello, I have a 1999 burb and I'm going through some a/c crap as well. First off, the high side valves are pretty common to leak if you have been putting gauges on and off. There is a little rubber tip to the valve that tends to come off and stick the valve open. It is fairly easy to replace. The whole valve unscrews with a wrench. You need to have the refridgerant reclaimed first. You can also try to remove what ever it is that is stuck by using a pick tool or small needle nose pliers. Does your compressor engage? If you have a good charge on the system and it is not engaging it most likely is the a/c cycleing switch that is located at the top of the accumulator/receiver drier. To test this unplug the wireing harness connection at the switch and connect a jumper wire between the two wires on the connector. Turn on the a/c and see if the compressor comes on. If it does replace the switch. You can probably get one at a local auto parts store for about 20 bucks. I just did the same thing and you don't have to reclaim the refridgerant either.
I hope this helps but if not I need to know more information. You may have blockage in the lines. Is the compressor noisy?, can you hear a change in the blower when you go from heat to cool?, do you have rear a/c that is blowing cold? Stuff like that. Good luck!! Roak

[jbsmithsa]

Thanks for the feedback. I will check the valve to see if something is lodged in it. I believe the compressor is engaging but will double check it this weekend. And yes, the rear A/C does blow much colder than the front. I have not noticed the compressor making any noise. I will check to see if I can hear a change in the blower when going from cool to heat.

Thanks again.

[jbsmithsa]

I checked and the compressor is engaging and appears to be working fine. The rear a/c vents are blowing cold air and the front are blowing warm. Can someone point me in the right direction or do I just need to take it and have it checked by an a/c tech?

[tank69]

a/c cycleing switch that is located at the top of the accumulator/receiver drier

Can you tell me where this switch is located? I am having the same problem, however, the compressor is NOT coming on with either front or rear AC. I have a 98.

[jbsmithsa]

I don't know where it is. I think I finally found a good a/c shop here in San Antonio and plan to take mine to them to see if they can help without giving me the standard, "we can fix it for $1,000 to $1,500".

[Ketch]

Same problem with my 99. The front is warmer than the back, although neither are very cold anymore. I noticed oil around the high side access port and twisted off the cap. It popped off and out spewed freon. Looked down in there and looks like the schrader valve is crooked like it was knocked over. Don't know why this valve would get bent over as nobody (to my knowledge) has ever touched the AC on this truck.

As it is high side - very high pressure - I'm reluctant to try straightening it. Pulling the valve off means loosing the system charge. Has anyone done an evacuation on this? How do I add the right amount of refridgerant oil as it seems to have lost some?

[Fernando77]

Hey, I'm having A/C problems as well on my 1990. I have a new compressor and a new evaparator. But I'm still having problems. Can you give the the address and ph # of the A/C shop you may use.

Thanks