thats true for ac operation...but the compressor also runs in defrost with heat on...i know that for a fact and from experience and when i get some time i'll post the source i got it from

You didn't answer my question on what temp you tested it at, Yes in the summer when its 50 or 70 ot 100* F out side It will turn on with the defroster with the heat on Yes i know.

But is wants to know if and if at what Temp it will not kick on. and the Factory Service Manual States 43*F.

Let'* keep in mind that each of us may have a different year car. That temperature might be different. GM did redesign and improve/change many things year to year.

Yes good point Bill.

bandit01 -what year and trim level is your car?

it was 10 degrees, and mine does it when its well below 0 out too and its not just my car that does it...every domestic car that ive worked (and many imports) on in my career does it...and i made a mistake earlier...it acts a a dehumidifier not a humidifier, sorry for that mistake....i have talked to my boss, who is an ASE master tech in all areas and several people that I work with who are all also ase certified and have been in the business for 20 or more years and they all agree...if the compressor does not run now in defrost with the heat (it is able to defrost your windows because it sucks the moisture out) then it won't run in the summer...it running during the winter is how i found out my ac compressor clutch is bad, it hasen't been above 30 degrees since i bought the car in at the end of december

i have a 99 sle and a 94 sse and both their compressors run in defrost

yeah um i know that, but when its Cold, mine does not turn on.
and every car iv ever been in, in the winter below a cretin temp does the same thing.

And i would know when mine turns on for two reason.
1: i can feel the power loss.
2: i can see my RPM'* / Volts drop.

and it doesn't do this untill the temp is warm a nuff.


Edit* unless there is a two stage run, IE, it runs slower and does not draw as much power to run it. But once again, wouldn't the fans kick on low still?

It says that the Compressor will Not kick on unless its 43*F

i looked deeper in and it had no other temp things or any more about when ti will kick on far as cold Temp thing goes.

I will look again when i get home today.

i don't always hear or feel mine click in (until my clutch started to go bad, then i could hear it all the time while it was running), but if you look under the hood, it should be cycling...i'm about to go on my lunch break so i will check on the fans...although if it just cycles on and off i wouldn't think they would kick on till it stays on for a longer time