i first posted this on the general board before i found out there was a board just for elec. probs. hopefully i'll get more replies here anyway when i start the car the a/c compressor comes on even though the switch is in the off position, if i slide it over to on, like in max or normal position then back to off sometimes it will go off but turns itself on in a few sec. if i leave it in the off position it will blow cold out the floor and console vents, if i put in max it works like it should, basiclly it is always runin no matter what i try. thanks for any replies

 

Need to know what engine. Some versions use a relay, others only 2 switches. After reviewing schematics for all three versions I have come up with only a couple of ideas. First thing is if the switch in the control assembly has a problem keeping 12 volts to the comp, or you have an ECM controlled version and it is getting a command from the ECM to keep the comp relay energized. I doubt it is the relay if you have the version that uses one. They rarely stick in the on position, but it is remotely possible. If you can give me vin eng code it helps. Keep

 

thanks danno, its a 87 iroc w/ 5.0 tpi lb9 center bolt valve covers. i was checkin out the head controller and noticed that the large disc shaped (thing) lol right on top got very hot, like ouch, and there is a power drain cause the alt gauge dropped lower than its normal position, other than not shutting off compressor everthing else works fine, thanks

 

You are talking about the switch control head inside the car? That is the only thing I can see from the diagrams that would cause the comp to stay on all the time. A failure of the pressure switches would still allow you to shut it off by the switch. Unplug the 25 amp fuse in the fuse panel marked HTR/AC and see if the comp turns off. This will make sure there are no internal wiring shorts in the car causing the problem. Sounds to me like you found the prob, if it is too hot to touch it's probably bad.

 

thanks for your help danno, yea it seems to be the lever that slides from MAX to NORMAL to BI-LEVEL there is a round disc that seems to switch these functions, i turned it on at night and it sparked and smoked from this area on the controller, i unpluged the power source to the controller till i can find a replacement, this also turned of the compressor. if anyone has one let me know, thanks for your help danno

 

i have a wrecked 85 Iroc that i could pull the heater/ac controls out of, if thats what your looking for, i am not sure if it will work on yours, can someone confirm this? if so, i would be willling to sell dirt cheap

Caleb

 

thanks caleb, i'am not sure if it will work or not, i've looked in a classic industries catalog and they list all other years with A/C but they list 87 w/o A/C, so i don't know if they are intercangeable, i'am not sure but when you turn A/C on the fans come on so it might go through the ecm, not sure about that, but if thats true that would possibly make that specific to some years, maybe i don't know lol