Since my H3 was new, while running A/C turning the temp control **** a couple of clicks from the full CCW position (cold) would result in a slightly less cold air flow. Just like you would expect.

Lately turning that **** even one click results in hot air blowing. Seems to me that the cause is likely to be:

1. Control module
2. Control ****
3. Wiring between 1 & 2

Any suggestions for troubleshooting? Any chance the recall wiring harness might help?

 

Yes, it includes the harness and resistor module.

 

The recall will not address the temperature control issue; it only addresses the fan speed. Here is the info you need on the temp control issue you are having: https://www.hummerforums.com/forum/h...p-28289/page4/
Scroll to post #18 for info on a Service Bulletin regarding the issue, and post #28 has info regarding an updated part number for the control module, but post #35 is where you start getting info on a DIY procedure on how to fix it.