Heater Controls

grose67 · May 17, 2009

The position on my heater/AC control seems to be screwed up. I can set it for the AC to come out the dash vents and it works fine for a couple of minutes, but then the air flow seems to get directed elsewhere. I can turn the switch to defrost and after about a 5 second delay I can hear the door close in the duct work. When I switch it back to dash vent it works fine for another few minutes then goofs up again.

bill190 · May 17, 2009

If you have an electronic A/C control...

Then you would have switches, an electronic control, then the door actuators.

With a multimeter I would check the switches to be sure they were turning on/off when pressed and not staying shorted on.

If these were easy to clean, I would disassemble the switches and clean them while I had it out.

Then I would examine the wiring.

Then look at the door actuator in question and see what was going on. Then perhaps try moving the actuator to a certain position, then watch what it was doing. Then maybe try again with the switches disconnected.

See if the switch control is making this happen. Or if it is the control unit making this happen.

Then I would monitor the electrical connections to the actuator and see if it was receiving an electrical signal to move, or if it was just moving on its own.

Basically find the problem by testing. I would also use a Factory Electrical Diagram for this.

Your alternative would be to take it to the dealer for repair or play "guess which part is not working". Just start replacing parts until you get lucky. The only problem with this is you may not be able to find where certain parts are located (the factory service manuals and electrical diagram books show what part is where).

ss502gmc · May 17, 2009

I have a similar problem with my 01. No matter where i direct the air flow it only comes out the defrost vent. But i know its one of the actuators as this problems been fixed once already and lasted a month now doing it again its so frustrating but i dont have the money to fix it now and supposedly its a pretty big job.

bill190 · May 17, 2009

I have a similar problem with my 01. No matter where i direct the air flow it only comes out the defrost vent. But i know its one of the actuators as this problems been fixed once already and lasted a month now doing it again its so frustrating but i dont have the money to fix it now and supposedly its a pretty big job.

I certainly understand not having the money to fix something!

What I would do in this case (if I could get access to the actuator) would be to manually position it so the air goes where I want and just leave it in that position.

This would be a duct tape, screws, coat hanger, or whatever worked to hold it there thing.