I've been having ridiculous A/C problems for about a month now. refilled it with freon and vacuumed out twice. had Lexus use their really nice A/C machine and flush out everything and vacuum everything and change the A/C oil and freon and it even checked for a leak check and nothing. Something is eating up my freon and the main concern is that my A/C clutch is getting NO POWER whatsoever. Tried the light trick on the fuse to see if it has power and its the only part of the A/C system not receiving power. I've heard a possible body control module is messed up, could be a bad ground somewhere, or something with the control circuit for the compressor clutch. The compressor does NOT turn on at all. The compressor is in fine shape. It came on last week when we were tampering with the GM Tech 2 and it worked for about a day then it just stopped turning on the compressor again after about 24 hours maybe less. When it was on it blew ice cold air so there is nothing wrong with the compressor. For some reason its either not getting power, well i know its not getting power and the computer or BCM or something, the car does not acknowledge that a compressor exists. I'm not sure but is there anyone out there that can tell me some steps to do to examine this SOB and see what the ultimate problem is. I've had 3 shops look at everything except the BCM and electrical system. They all did the routine leak check and all the stuff you can do with the fuse box and just looking at the compressor.

 

could be a number of things. could be a bad compressor clutch and is shorting out the circuit through the computer. the computer may be sensing something wrong in the a/c circuit and not engaging the compressor.

 

do the electric fans come on as well when the compressor isn't turning on? Bad low pressure switch? just a guess.

 

fans come on.

how can i check for this? is there anything i can do right now while my car sits outside?

 

try jumping the compressor with a 12 volt source, and see if it works. then see if the fans work and if the compressor clutch cycles in and out.

 

i hate to pry. but do you have a suggestion of the best 12v i could use. do you mean possibly like someone elses car? also, where would i touch the positive and negative terminals?

 

i would say battery, but that cannot be done. try something out of the fuse box to use and then just ground the other connector pin. if it does not seem to work, then try reversing your connection. you did say that the compressor worked at one time, so if you jump the compressor clutch it should work. and if it does not work, then it could possibly be a shorted compressor clutch

 

yeah we made it work somehow a week ago with random tampering with the GM tech 2. ill give that a try thanks man. ill report back

 

i think with the tech 2, you can tell the computer to send a signal to the compressor to turn it on, but i am not sure. if the tech 2 can turn the compressor on, then there should be no problem with the wiring from the computer to the compressor. the problem would be with the computer or something else corrupting the signal to the compressor

 

what about that thing thats in the fuse box that is hooked up directly to the battery, that little round terminal thing. will that work too

i think thats what it is. what are the possible causes of this, is it mostly a corrupt BCM or is there other things that could affect it?

 

aslong as it is a 12volt source, you can use it. the bcm could be corrupt, but could be other things as well. what you need to do is find someone that knows electrical and how to use a computer to pinpoint it. i see you said that the fuse has no power. if that is the case, find out what supplies the fuse. could be something as simple as a broken wire in the harness

 

ok ill see if i can ask around town.

 

let me know what you find so i can give some more suggestions

 

mine was having problems too, it would work for 2-3 days then out for a week or more... i took it to a shop and they replaced (i think) the low pressure switch & a relay for the a/c clutch...then unplugged my batt for 1/2 an hour and its worked since....

 

my relay is fine. but how much did it cost you to replace the low pressure switch? i may just have a shop see if that may be the problem if its super cheap. im trying to diagnose it myself right now since im out of work