I dont know much about the ac system. My compressor is running fine, my high side tubes are getting really cold under the hood it is holding steady pressure but I get no a/c in the cab. It got emptied when i did my plenum fix and i just filled it up with r-134a i got at store. it had moisture remover, oil and the refrigerant in the can. What could be my problem?

 

Your problem is you didnt take it to an AC shop and have them evac and charge the system properly.

 

If the lines are getting good and cold it's not a problem with the charge. More likely a vacuum issue that is cause the doors in the duct work to not open/close. Check for vacuum lines you may have left off or broke during the plenum fix.

 

I tagged all my lines when i did plenum fix. But when i have the dial set on blowing towards head setting, it will blow on my face then switch to defrost by itself sometimes. You think the flaps in the duct work is not working properly. Oh and my thermostat dial is really touchy. I can have it set all the way down on cold and turn it up like three or four notches it will blow almost pure hot air. Is it supposed to be like that? Could i have a thermostat problem?

 

Well how much do you think it would cost to take it to a repair shop. The compressor is fine and there are no leaks so it shouldnt cost that much right?

 

Depends on what the problem is. Sounds like you have vacuum issues. ALL of the controls are vacuum powered. Seems like some are too sensitive, and others simply are not doing what they should...... check for vacuum leaks in the lines, under the hood, and under the dash.

 

What happens you turn the AC off but leave the temp **** all the way to cold? I think what is happening is that the heat is not turning off. When you run the AC all it does is bring the air to ambient temp.

 

yeah it just brings it to ambient temp. When its cool outside it will get cool in cab, if hot outside then hot in cab with thermostat control turned all the way down. I live on the gulf coast of MS and work in a shipyard its way to dam hot to not have a/c in the truck.

 

What year is your truck? Seems at some point, they went to an electronic blend door actuator????

 

they did go to an electronic blend door in 98. at least my 2000 is electronic.