I apologize that I am bringing up a topic that has already been discussed here, but it has been a few years since that forum was active and I was hoping to get some fresh perspectives. Whenever I move my H3 HVAC temp control one click from the far left, the blend doors change so that it is only blowing super hot air. When I move my blend door control **** one click from all at face level, s a similar thing happens - the controller sends all of the air to the defrost setting. The long existing thread on this topic is located here: https://www.hummerforums.com/forum/hummer-h3-17/problem-ac-climate-control-need-some-help-28289/page4/.

Here is what I have tried so far:

• Tried soldering the 68ohm resistor in line with one of the wires to the temp controller. Did not help.
• Replaced the HVAC control unit with the new part number for it.
• Took apart the blend doors - they're working fine and there isn't really much in the way of electronics in them to fail.
• Replaced the blower motor resistor that was recalled. I actually did this myself prior to the recall because it had burned up.

One theory I read is that maybe this is a voltage issue. It is super frustrating though!! Any help would be appreciated.

 

Did you actually have the recall work done? The new harness includes a new resistor and that would be different than whatever you did depending upon when you did it and with what?

You can order the harness yourself, but your VIN history would still show an open recall item.

 

I just made an appointment for next week for the recall. I haven’t had the recall done yet, and ironically a notice for it showed up for the first time last week. 🙄

 

had the recall work done today. Still having the issue. Left it with the Chevy dealer and having them troubleshoot. I’m so over this issue! Winter is coming up and I need the control of temp and mode. I switch between the hummer and my m4 every few days.

 

It could easily be the blend door actuator motors. Even if they "seem" to work, they can malfunction. Luckily, they are relatively easy to get to and replace, and they are also relatively inexpensive.

 

Yeah we will see what the dealer comes back with. I took one of the actuators apart, and like you said it seems like its working properly, but maybe not. I may just tell them to replace all 3. i'm tired of messing with it.

 

You have a m4, yet drive a H3? I see where your drama is coming from.

 

Hah. Well I actually enjoy driving the hummer, but I also want to just keep the M4 mileage low because I'm planning on never getting rid of that car (same as we have done with the hummer). The M4 is great, but it is not the most practical vehicle. Convertible stick shift wrapped in yellow.

 

I drive my H3 all year with my sunroof open, except when it's raining or snowing. If I feel a bit cool, I turn on the heat, and If I feel a bit hot, I turn on the ac. The best part, I can control the temp with the fan speed and/or on/off button +open/close a window.
I'm not a mix type!
I either need some hot air or cool air.
I only called you out, for the simple reason that you are not compatible with the:

 

i love this hummer. It’s the longest we have ever met a car. It was my wife’s primary driver until we got her a 3 series bmw in 2013 and then an x5 in 2016. So she drives the x5 and I rotate between the h3 and m4. Mostly I drive the h3. It’s absolutely spotless inside. I just like how it drives, and for being at 150k miles it’s really been super reliable. Very few issues.