Hi guys, I'm new to the forum and have so far gotten some great info, but this recent problem is driving me nuts!


2002 GMC 2500 HD 6.0 gasser:


51,000k


About a month ago the AC compressor went south and would not let the truck idle as it seized. I cut the belt to the compressor and drove around untill I could get if fixed. Problem solved right?


Well since the compressor replacement I come out every mornig to a dead battery. Now this only happens if I leave the A/C on when I shut the truck down. After testing this for many nights I believe the A/C clutch, which is activated electrically is sticking on, killing my battery over night. Nights that I shut the AC off then shut the truck down its fine.


I searched for this problem all over the board and could not find anything, but I do remember hearing about this as a possible problem any ideas?


Yesterday I came out and along with the dead battery the truck would not idle again, without tapping the gas. So I think the compressor is headed out again. I've had it with this and called GM Roadside and had it hauled to the dealer.


Anybody think the compressor clutch is a possibility?? I need some backup when I tell the dealer to give me a new $700 compressor and a new batter for their work killing mine!

Sbarshie,


If you shut the truck off the compressor magnet should denergize.


If it's not, then it will kill your battery quickly because it draws a lot of juice to remain on.


Try this, open the hood,turn your key on with out starting truck, then turn on your AC button, you Should hear the magnet engage and if you look at the compressor while some one hits the AC button for you, you can actually see the magnetic clutch move.


Now try turning off the AC switch and verify that the clutch disengages. If it does turn the switch back on again and this time turn off the KEY, the clutch should disengage again. Your's is probabbly sticking on and draining the batt overnight.


Now WHY it's sticking is the question.


Could be the compressor, or the switch or a shorted wire somewhere in your HVAC control, that is the question.


The batt may be toast from repeated drain and rechaging cycles.


As to why your truck wont idle, it might be a coincidence and it could be something else all together.


Give it to the dealer to figure out, that's what warranty's are for.


Good Luck


Diesel Dragon http://www.dieselplace.com/forum/smileys/Cool.gif

please describe.... "cut the belt" just a little.


Thanks

could be a sticking A/C clutch relay... if comp is on with key off, find relay in underhood box(driver's side) and remove relay. One thing you didn't mention.. do you have auto a/c?, if so then blower motor could be running even with key off, which is usually blower control module, common prob with cads, buicks and such with auto a/c. Module is under right side of a/c case, have to remove right under dash cover to see it, should have 3 small wires and 2 heavy wires running to it, about 3 inches long and roughly 11/2 inches wide... BTW if comp is going again MAKE DA** sure they flush complete system

Thanks guys, I am checking the clutch today, plus i pulled the relay. We'll see what happens. If the copmressor goes I can still cut the belt that goes to it. I have a seperate belt just for the AC comp, its not part of the serpintine for everything else.

Try unpluging compressor clutch coil connection overnight and see if battery still dies. If it still does then problem is not in that circuit.