AC trouble-99 Denali -need help

[Ohio Bird of prey]

The line under the air box going into the firewall is cold. However there is no cold air coming thru the vents. Blower is working fine. Is there a trap door somewhere that is not opening allowing the cold air to blow into the cabin? Where can I find drawings on all this crap behind the glove box? Instructions on how to get to this stuff would be great as well. I am a DIY guy but electrical and AC stuff not so much. Please ask me anything to help solve this issue.

 

[SunlitComet]

You have rear a/c too or just the front? And if rear too how is it? I can get you drawings and diagrams too but need to know if you have rear.

 

[Ohio Bird of prey]

My Denali has both front and rear A/C.
I just checked and the rear is cooler than the front
but not by much.
I dropped the glove box yesterday with the intent
I'd pull the actuator out and turn the door by hand
to let the cool air go thru the vents but what I pulled
was some sort of temp sensor it had a bunch off coiled
wires on it so I put it back in. Can't fine the damn actuator.
Thanks for your reply and I appreciate any help and the diagrams too.

 

[gpracer1]

What is the whole history?
Was it blowing cold, then just stop working?

 

[SunlitComet]

Uh do not touch the coiled wires. It sounds like you accessed the blower resister. The temp door motor is block in by dash bar on bottom of unit. Anything else different you notice. Compressor constantly running?

 

[Ohio Bird of prey]

The compressor turns on and off and on and off......................and so on.
It won't stay on very long at all.

 

[noJeepshere]

So, there is air blowing through the vents just not cold air? Since you say the compressor is doing very short cycles, and nothing is very cold, sounds like your a/c system is low on refrigerant. Or if you just had it serviced, it's been overcharged, which gives the same symptoms. I'm a diy guy but I don't touch a/c stuff because of the delicate nature of the internals in it.

 

[SunlitComet]

delicate nature my ass! get yourself some a/c tools and dig in. if you need tech manuals i got them!

Larry, i don't suppose you can get temperature of each pipe in the compressor. Also if not is there a huge temp difference between the two with you hands or a minor one. and what is it like just as the compressor shuts down. and lastly is it on more or off more during all this. of course if you can get your hands on a gauge set that will me more informative.

 

[Ohio Bird of prey]

Thanks for all the replies.
I'm going round up some gages and report back my findings.

 

[YUKON1999]

mine was doing the same thing i had it tested and the guy said it was fine but it def was not so i recharged it and now its perfect. so i would try that if you havent