Hummer Peeps,

I asked this on another forum but didn't get a fix.My AC is blowing nice and cold. No problem with the blower, but the heater isn't working. Only blows cool or cold air. I checked the heater hoses and they are both hot. I ran the vent calibration and I hear the actuators opening and closing, but still no hot air afterward. Is there one actuator that controls the air temp? If so, which one is it? From the parts sheets I've seen on other threads, it looks like there are 3 or 4 actuators. It looks like 2 are the same and others are different? I hope someone else has run through this and has a fix. Thanks.

Hooty

 

look under the dash behind the glove compartment. there is a solenoid there. there is a recall on it. mine was burnt

 

a while back there was a post on this with details. i cant find stuff in search but i saw it. they are stepper motors controlled by the canbus mentioned in another post here.
im looking for info in service lit but cant find it. someone will b4 me i hope..
the other post was like yours and i think he had to reset the motor gears?? just from memory. try searching, maybe youll do better.

check/ search "blend door actuators" its about h2 but it has same type system. 2-3 posts.

the recall is about blower speed resistor connector, not your problem. no solenoid there.

 

There are two actuator motors that control the temp. Look up under the dash on the driver side and you can see them; watch them to see if they rotate when you change the temp setting (there is a third actuator higher up, that controls the outlets, and a fourth over under the passenger side dash that controls the input source). On mine, when I tried to get hot air, I could hear the actuator motors trying to turn, but binding/clicking instead, and all I could ever get was cold. I bought 2 actuator motors on Amazon, for about $25 each (here: http://smile.amazon.com/gp/product/B...ilpage_o03_s00 ). Installed, ran the calibration process, and the problem was solved.

 

...on my '07 H3: no heat at all. Also, mine will not change the vents that it blows out of (it's only blowing out of the dash vents, and making that awful non-stop clicking sounds). How hard is it to replace these actuators? I've looked for a H3 manual but cannot find one. Any help would be greatly appreciated on this (pics, diagrams, instructions, etc.)

Also, my hvac blows intermittently, and seems to have a mind of it's own. I replaced the hvac resistor plug(the GM recall, I just used the parts they have now), but that didn't change a thing.

Again, any help would be greatly appreciated. I want to do all the work myself but have no idea how to get started...

Thanks!

 

The actuators are easy to replace. Unplug the wiring harness, remove two screws, and pull it out. The top one is a bit harder to get to, but still doable without any other dis-assembly.

 

Thanks 650Hawk! I found a manual for my Hummer here on the forum and am going to get after those actuators. I think I need to replace them all because it won't switch from dash vents to floor vents at all and just constantly make this dull clicking sound.