I have a 2001 Suburban (2500 LT 4x4) that has a rear heat cool issue that I can't find after days of searching the internet. I'll try to keep this brief as I've found that too much information can muddy the waters.

The front AC works fine. It gets hot and cold as requested. The rear AC can't decide what it wants to do and ultimately winds up hot. I pulled the rear panel off the cargo area and observed the blend actuators. The actuator that controls airflow to the roof/floor works fine.

The problem is the actuator that opens and closes the temperature blend door just constantly cycles hot to cold. I tried pulling the HVAC fuses and relearning the actuators. I tried disconnecting the battery and touching the cables together for 10 minutes and then tried to get a relearn. But the problem remains. Since the actuators are the same part and since the roof/floor actuator works fine I swapped it with temperature actuator. The roof/floor still works fine when running the swapped in temperature actuator. And the temperature blend door still constantly cycles hot/cold even when running the actuator from the roof/floor. Any ideas where to go next to figure this thing out? Attached is a video that shows what the actuator is doing.

Link

 

If it's any easier I added a link to the video just above the attachment

In the video I am not moving the temperature controls, the actuator is moving on it's own. Also it does not matter if the AC is on or off. It also does not matter if I set the temp full cold or full hot or anywhere in between. I get the same swing in the actuator.

 

Is the blend door possibly the issue? With OEM plastic doors they typically break near the drivers. If so blenddoorusa.com does sell a rear HVAV kit for 2000-2006 models.

 

1. I watched your video.

2. I have a little experience with the "beloved" GM actuators; I had under-dash issues with actuators on our 1994, 2005, and 2014.

3. What you stated above seems to rule out the actuator itself; it appears that the actuator is getting an electrical signal, and your clearing the ECU to re-set didn't help. Good luck on ANY GM dealer having a clue with electrical stuff; our ONE try with dealer service on an intermittent non-closing sunroof on our 2005 SUV resulted in dealer stating "we have absolutely no idea", and I fought to get a refund of such charges.

4. Here's the workaround I would do, especially if the cover over the rear actuator is somewhat easy to remove. Disconnect the wire harness to the rear actuator. Turn the actuator with a screwdriver to get it in the position you want, like heat for the winter. Then, once it warms up and you might want AC, again turn the actuator with a screwdriver to get into the AC position. I did similar on our own 2005 GM when it did have a bad front actuator.

 

Thanks for the reply Blenddoorusa. My blend door seems to be working fine and I don't feel any issues when I pull the actuator and flip it by hand. But I do have a blend door issue on my sons 2000 Civic so I'll check out your site and see if there is anything there for Honda.

 

Thanks Cusser I believe it about the dealers inability or just unwillingness to work on older vehicles. . It's frustrating that these systems seem to be more complicated than truly necessary. I have considered putting a hole in the cover with a small cover plug and just manually moving the door as needed with a long screwdriver. I'll keep researching it, the answer is out there.

 

We do not currently have anything for Honda but, that is something we could certainly look into for you. If you go to our website there is a custom request form that you can fill out and I will get it to the correct team to see if it is something we could make for you.

 

Dealerships seem unable to diagnose electrical systems or think "out of the box", from what I read.


Agree.


That's a great idea. On our older Yukon I left the under-dash cover off (removing that was pretty much the toughest part, had to grind my 5.5mm socket shorter at both ends to unscrew one of the retaining screws); was out of sight, and I could switch the actuator easily with a screwdriver. Here is Arizona, we do have four seasons: warm, hot, hotter, and hotter than hell - so I could leave in the AC mode most of the year.