Hey guys,

I think I have a problem with my A/C. It seems as if the compressor is always running. It is constantly cold, with "alot" of condensation around it and the lines. So much so, there is always a puddle of water under the truck when it is parked. I know this is normal if I have been running the A/C, but I have not. I have only run it once to make sure it worked. That was about 2 months ago.

Do I have a problem, or is this the way the Duramax is?
My 8.1L did not do this, nor did my 1500 with the 5.3L.

For some reason I have only really noticed it recently, I don't know how long it has been doing this.

thanks in advance for the help

maybe the switch is stuck on?? no, its not normal for the condensation to be like that when its turned off. the compressor should not be running 100% of the time.

just to test this you might find the fuse for your A/C and pull it and see if the compressor goes off... or just take it in to the dealer if you don't want to mess with it.

You did not mention, do you have the auto dual climate control system?? In my 05 I have this system and the A/C compressor runs all the time the engine is running unless the system is manually switched to off and outside air if I recall correctly.

The A/C is used as a dryer for the air, to remove condensation from the air coming into the truck. This has been so for many many years of cars & trucks with A/C, however this is the first vheicle I have seen which runs the compressor this much. This is a good thing when trying to defrost windows and such, dry air defrosts better.

As to the condensation, there will ALWAYS be condesation which forms on the low side compressor lines when the system is running UNLESS you live in an area which has a humidity content in the air which is very low (I would guess less than 60 or 70%). Of course since the A/C by it's very operation is removing water from the air which passes through it, there will be some drainage of water depending on the humidity of that air. The higher the humidity, the more discharge it will produce.

I hope I have this answers your questions.

John

P.S. on Edit: Has nothing to do with the Duramax Package in my opinion.

You did not mention, do you have the auto dual climate control system?? In my 05 I have this system and the A/C compressor runs all the time the engine is running unless the system is manually switched to off and outside air if I recall correctly.

VERY good point!!!

thanks guys,

just got back from the dealer, everything is fine. I do have the auto climate control, and that is the culprit. service guy said the system will try and keep cabin temp where the dial indicates, whether it is in the auto mode or not. if the ambient temp is greater than the setting on the dial, the A/C compressor will run even if it is not in A/C mode. the only way to bypass this is to turn off the system, or to manually turn off the A/C (turn it on, then off)

he showed me this, we sat and watched the compressor engage and disengage. he even mentioned how poor of a design this is.

thanks for the help

Also note that any time the recirc button is pressed, the AC compressor will engage ........... EVEN IF THE AC BUTTON IS NOT PRESSED. The general feels that the AC compressor must be engaged any time the recirc is engaged. So if you have the AC button off (light not lit on my 2002), and you press the recirc button (it is lit), the AC system will be active.