Hello World! Sharing my experience with what I feel is a neat vehicle. Does what it does for me. The A/C is a intermittent. Things I have done so far:

Asked the drivers (two) if they have ever smelled the good old electronics smoke, and that is all.

Options:

Check the wire harness under and behind the dash board.

Check the resistor, attached to the same.

Check the clutch on the air pump engagement.

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I plan to do these things tomorrow or the next. Do you fine gentle-people recommend anything else? Thank you for the time. I hope that we can build a correct database for ppl trying to troubleshoot the same problem.

 

Welcome to HF.

Did you get your recall notice about the HVAC harness??? Might want to take a look https://www.hummerforums.com/forum/h...call-gm-35541/

 

Need more info. What do you mean by "A/C is intermittent"?

-The fan only blows intermittently (both heat and cool)?
-The fan blows OK, but the A/C (cold air) only intermittently works?

There are 2 common issues with the H3 climate control system. One is that the air temp is only cold when the (left) **** is all the way to cold; turning it even one click towards hot immediately goes full hot. That can be solved with a small resistor wired into the harness behind the switch (do a search). The other is the fan (blower motor) control resistor/harness, which has been addressed by a recall from GM.

As Doc said, have you had the recall done?