i need help with my a/c unit in my H3 Alpha...it blows a combination of cold air and then all of a sudden it blows warmer air. Seems to do this for most of my drives here in Phoenix and its making my ride very uncomfortable and frustrating. I'm looking for any advice or suggestions to tell the dealership techs...tsb, personal history, ideas? The last time the dealership just replaced the heater box and now the "hot pockets of air" are back. Thanks everyone

 

Not sure which dealer you are going to. I have had good luck with Lund. Sorry, no troubleshooting ideas for you.

 

Mine does the same thing. I'm guessing that its a lack of airflow over the condenser. I think Hummer skimped on the cooling system on these trucks. My a/c has gotten better since they replaced the fan clutch, but in traffic it will still start to blow warm air until the fan clutch kicks in to pull air across the condenser. I'm thinking about trying an electric pusher fan to help things out.

 

I politely disagree. I don't have these issues and I live in Phoenix as well. The air is always cold. You may also have issues that need to be checked out.

 

If the compresor is cycling on and off, it may be because it is low, or high. I would guess it might be high, since gas expands with heat, and it's hot in your area. Try releasing a small amount of freeone, or adding some.