Climate control panel off, but a/c compressor is kicking on.

[92470]

My truck (1987 V10) was idling today and I noticed I could hear the a/c compressor kicking on and off. My climate control panel lever was in the "off" position, and the fan lever was in the "low" position. Temperature lever was all the way to right to heat. Anyone have any idea why my a/c compressor would be kicking on and off when I had nothing on? I know it operates with the a/c on, and also defrost, but my panel was off. It was working also because I felt the lines and they were ice cold. I just unplugged it at the compressor until I could figure out what the problem was, but any suggestions? Thanks for any help!

This new problem is on the heels of my no high beam problem I am trying to solve as well. I swear sometimes I wonder why I just don't buy a new truck and end the constant frustration of a new problem every week with this one.

[87 STEPPER]

Im thinkin bad switch!

BTW....The constant frustration of a new promlem every week is probably offset by the constant frustration of an empty wallet when buying new!

[92470]

What switch are you thinking could be bad?

And by the way, your quote was well said. I think we've all been there though!

[87 STEPPER]

Im trying to remember it's been awhile since i've been into one but The mode selection switch is a multi selection sw. when you go from off to say a/c it select your a/c system vaccum and the electric circuits at the same time.

You will need to pull the entire a/c cont. panel out and look at the electric switch thats mounted on the back side of it. thats the one that is probably bad.

I've seen them where the connector has got so hot that it will melt that may also be the problem.

[92470]

I switched out my climate control unit about 2 months ago due to I was trying to remove the lever chrome tabs to put on a much nicer face than was on mine, and I broke one of the levers so I had to get a whole new unit. Found a good looking one at pick n pull and put it on, but haven't drove the truck much since then. I wonder if it was bad? I saved my old broken one with known good switches on it. I guess I could move them to the new one and see if that works. I just didn't think anything in the control panel could cause my issue. But I'll try it. Thanks.

[BLE 'BURBAN]

The a.c. compressor is designed to cycle every few minutes to help keep itself lubricated and the refrigerant flowing a bit. it helps to prolong the life of your a.c. system.
The older models (84 &older) didn't have this feature.

[92470]

Originally Posted by BLE 'BURBAN

The a.c. compressor is designed to cycle every few minutes to help keep itself lubricated and the refrigerant flowing a bit. it helps to prolong the life of your a.c. system.
The older models (84 &older) didn't have this feature.

Mine is now cycling all the time with everything off though. I don't think they were designed to cycle anytime the engine was running were they? I know they cycle on defrost and a/c, but not with everything off, or let's say with the heater on. I've looked all through my G.M. dealership service book, and can't find where it states this. Anyway to clarify? I would like to know for sure because I am going to take out the climate control panel tonight and switch out my electrical selector switch tonight. I appreciate the info, I just have a hard time believing they were designed like this. I never seemed to hear it cycling all the time before?

[87 STEPPER]

No thats incorrect i've owned many types of GM vehicles and years and none of them are designed to cycle the comp in the OFF position. As you stated in your original post when in the defrost position the comp will and is suppose to cycle.

[92470]

I was pretty sure it wasn't supposed to be on every mode. I'm going out tonight to replace the selector switch located in the control panel, and hopefully this will cure it. Can it really be this easy? Of course not, but one can hope.

[92470]

Originally Posted by 87 STEPPER

Im trying to remember it's been awhile since i've been into one but The mode selection switch is a multi selection sw. when you go from off to say a/c it select your a/c system vaccum and the electric circuits at the same time.

You will need to pull the entire a/c cont. panel out and look at the electric switch thats mounted on the back side of it. thats the one that is probably bad.

I've seen them where the connector has got so hot that it will melt that may also be the problem.

Well problem solved! I pulled out the climate control panel and sure enough, the selector switch had a burn mark about the round size of a eraser on the top of it. I swapped it out for another unit I had, and no more compressor cycling. I disected the bad switch and when I popped it open, it was full of gunk and green from moisture I guess. The copper connectors were really worn and al burned looking. Thanks for the direction. One more of the list!

[87 STEPPER]

Hey glad you got it fixed and glad i could help ya.