I'm starting to get caught up on major maintenance on the Hummers and am starting to get around to some of the small glitches that they have had since I've owned them.
2007 H3 3.7 5cyl. The A/C compressor turns on when either the A/C button is pressed ON and lit OR the Recirc button is pressed ON and lit but the A/C is OFF. It would appear to me that the c9mpressor shouldn't engage if the a/C button isn't on?
If I am correct, should I be looking at the control module itself or possibly wiring between it and the compressor?
I'm hoping this is a known glitch and you guys can give me guidance.

 

You can't count entirely on the A/C light. For example, the A/C compressor is engaged anytime you have the defroster on.

I can see the A/C coming on automatically with recirc on, to act as a dehumidifier (same as defrost).

That said I'm not completely sure, but I will try to check tonight on mine.

 

Was able to test this out and the A/C does not turn on for me with only recirc selected.

Have you performed the HVAC Controls reset/learn procedure?

 

Check the AC system for over or under pressure. If you or a prior owner put too much AC juice in (and even in some cases too little), the AC clutch can get get stuck and be unable to disengage. Or the clutch itself may be bad.

 

Air conditioning system automatically activates with defrost and defog:

 

Well, I guess it does turn on. I must just have missed it. Granted it was cold outside when I tried.

Thanks for the post hummerz

 

I've only used recirc on hot & humid days.

 

Just performed the HVAC reset/learn procedure and it worked like a charm. Thanks everyone.