Hey all,

So, Ill start at the begining. I have a 98 SLE. I worked in England from August 2008 to August 2009. The car was parked in a shed in MN over the year, with the battery unhooked and on blocks.

When I came back and started driving it this fall, it seemed fine. But the weather was average, not too hot to need AC and not too cold to need heat, so I didn't notice any problems. As it got colder though, I noticed problems.

On startup, the electronic display flashes, indicating a stored trouble code. (I have single electronic climate control, not dual) I tried to shift the air from the defrost to the vents, and to the floor. It wouldn't budge, it was stuck on defrost only. Also, it would only blow cold air, not hot. The Tech 2 said it was the Air Mix door, and so I diagnosed it and the book said it was the HVAC programmer that was ****. I called around, and got a local junkyard one for $50. (The stealership one was $479)

Plugged it in, and wala the vents change now! Its magic. But, the thing still blows cold air on warm startup. I dug further, and pulled out the glovebox to watch the Air mix door arm. Sure as ****, on warm startup it goes all the way to the left, thereby letting in outside cold air. I took a long screwdriver and coaxed it back to the right, and it will stay there, thereby giving me warm air.

I plugged in a tech 2 diagnostic computer from work, and it shows that as I adjust the temp, the air mix door counts change accordingly, which makes me believe that the programmer is commanding it properly, but for some reason the acuator just gets stuck on count 56. (0 counts is full hot, and 256 counts is full cold for those who dont know)

So, can the electric motor in the air mix door actuator go haywire? Why would it not do what is commanded? A new actuator is 60 bucks my cost through the dealership, so I dont want to put this part on it if it wont fix my problem.

I have seen through researching that sometimes the gears crack inside of the actuator, but would that be causing my problem if I can manually push the door closed while it is still atatched to the actuator?

Just looking for experience here, as Im sick of having to use the dcrewdriver everytime I get in the car for heat. I would like it to be fixed right.

The car has 160xxx miles on it.

Please let me know if you need more info or anything too.

THANKS!
Cody

This one has been moving down the list all day, so I am bumping it to the top for some attention.

Best thing to do is watch the air mix lever while changing the temp settings. Does the level hit something? Is it binding. Can you tell if it'* still commanding a move and just sitting there?

The lever will start moving on its own. Example: I start the car. The temp is set at 90 degrees f. The lever should stay all the way to the right for the heater core air to flow. It will stay there for 10 seconds, then randomly move to the left. I dont know how to tell if it was comanded to do that... any suggestions?

When I watch the lever move, about half way through the travel, it has a hickup, where it acts like it either hits something internally or maybe it has that broken gear syndrome, then it continues on its path.

I dont know how to tell if the actuator was commanded to move or if the controller is bad and it just starts moving, much like the headlight motors on the Firebirds. Sometimes the motor has the endpoint stripped, so it just keeps going and going, without shutting off.

I hope this makes sense. If it doesn't, let me know what needs clarriffied.

Cheers,
Cody

The movement should be vacuum. Take out the glove box liner and you should see the vacuum lines, small and all different colors. If I remember right, the red hose goes to a vacuum solenoid. I had a GTX here a while back that had heat only. I simply reversed the vacuum lines and he had cool air. Now that it'* getting colder, he will need to switch them again. This write up might help. https://www.gmforum.com/t279092/

I looked at the writeup. very nice.

However, the air mix door is an electric actuator. It has a DC motor in it, and the programmer plugs directly into the electric air mix door actuator. It sits on top of the duct, just above the programmer. When I take the glovebox out, I can only barely see it through one of the nickel sized holes in the metal framing...

Make sense?

Is this what your looking at?

yes sir! That is the electric actuator that is not doing its job on my car and making me cold when I want heat! haha.

From the looks of it, it'* not a serviceable part. Do you need a write up on how to replace it?

You are right, it is not servicable. You just replace it. But I want to make sure that with the conditions present, that this is the culprit. $60 is a lot of coin to me, and I doubt I can return it if it doesn't fix the problem, ya know? I was just hoping someone may have had this problem and can definately say this is the problem, or it is something else...