Will replacing the AC Control Unit fix my issue of no heat blowing through HVAC?

ID Status Date Year Make Model Transmission Type A/C Controls Public/Private
#14000 Closed 2007 Chevy Tahoe public

June of 2017, my AC went out…multiple codes thrown- ended up having a auto shop replace the front left door actuator. AC worked fine… earlier this year my AC compressor blew out… i had a shop replace the compressor, orifice, tensioner, accumulator, AC belt, and also the ABS control module (because my stabilitrak, traction control and brake – dash lights all display all the time)

AC worked fine afterwards…(stabilitrak, Trac ctrl and brake lights all still light up, as I have yet to take the tahoe to a dealership to have the thing programed with the proprietary GM programmer).
Lately, as it has gotten colder I discovered the heat will not work.
Air comes out of correct vents and blows at correct strength as I adjust.

I tried the fuse/recalibration trick this evening as a last ditch effort to correct my issue…

I took it to a shop last week who trouble shot the issue, this is what they said:
“vehicle has a heat and ac issue from side to side, we took apart the lower side of the passendger dash to gain access to the temperature door to see if they were stuck or broken? Doors are not broken we believe that problem is in the control head. If you change the temperature enough and put the system into enough variances it eventually does what you want. We would start with a control head.”

So im reaching, wanting to see if their are any other avenues that are more sure than the AC control unit. If not ill pull the trigger on ACdelco part # #25936130.

Any insight is greatly appreciated.


Although is is very possible that your control panel may have a problem, the  most common causes of your described issue are a faulty actuator, a poor connection at the actuator harness connector, poor terminal contact at the right junction box connectors and then a faulty control panel.  Keep in mind that something as simple as low engine coolant can affect the temperature at the vents.

Hard to second guess another shop when they have had the truck in their shop and I have not.  I am curious to know if any codes were present and if any mention was given in regards to actual versus commanded door counts?

Thanks for the feedback and insights.

No codes have been present with this most recent issue of no heat blowing.

The only codes thrown were emissions related at the time the hvac issues began (first with the Ac going out over a year ago as mentioned above).

Afterwards, and during I’ve had constant, but from what I’ve
gathered from the two shops I’ve had the Tahoe in, unrelated to the hvac issues.

The quoted text above was the only info given which may or may not (hopefully does not…) sum up all of the troubleshooting the repair shop did.
I picked it up after hours, and after relocating have now been to this shop twice. Great reviews for this particular shop, and I’ve had a good experience so far, but I’m feeling iffy on them getting it right. But thankfully – I have no idea what I’m talking about.

I can’t offer up too much more info, and at this point will look to order the AC control unit I guess. As I need my wheels, and the next time I take it in, doesn’t need to be for more troubleshooting…

I wish I had more information to offer up.

I’ll post back a follow up.


I would strongly recommend finding out if the shops that you are dealing with have scan tools than can communicate with the HVAC system and perform bi directional controls of the system.

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