Hello,
2007 Hummer H3. I am having a very frustrating issue with my H3 where I can’t get any heat out of the vents whatsoever. I have had the recall done on my blower resistor and harness and that works with no issues. Felt both heater core hoses and are hot and same temperature. Use my inspection scope to find that the blend door for cold/hot air working with no issues. Replaced radiator and water pump approximately 4 months ago, Replaced thermostat less than a year ago. Calibrated actuators several times. Temperature is where it should be reading on my cluster. Looking for new possible information regarding this issue primarily because I’ve been to the end of google trying to figure out what the issue is with no luck. I am new to the forum setting so please bare with me. Thank you in advance and any information is extremely appreciated.

 

Are you sure that when changing the blend **** the doors in the heater box are moving? Check the actuators on the outside of the heater box as you turn the *****. You can access them behind the glove box. There are three different ones.