Passenger blend door actuator

[marrober9]

I have a 2001 Bonneville and the passenger side vents only blow cold air. It is a dual climate system with the drivers side working perfectly. I pulled the glove box out and can see the actuator turn but not all the way. I would say it turns more than half way. Then it slowly returns to the front potion which only lets in cold air. I pulled the actuator out and I can easily open and close the blend door with my hand. For some reason when I turn up the temp even all the way up the actuator will start to open the door but then stops around half way then slowly starts moving back to the other position which is cold air. I have disconnected the battery for longer than 10 min to try and reset but to no avail. I also bought a brand new actuator and put it in but it also does the same thing.When it start to return to the front it turns a little then stops then turns a little then stops again. It will continue to do this until it goes all the way back to the start then it will just stay there. I do not know what to do now. Any help will be greatly appreciated. Thanks

[Archon]

It's possible that the temperature sensor for that side is defective. You could have it scanned to see what it reads, replace it, or swap the one from the driver's side.

[marrober9]

Were is the temperature sensor located

[Archon]

In the lower dash panel. There are two connectors. One for the light, the other for the temperature sensor.

[marrober9]

Yea I found it I have to drive out of town so wont be able to do it tell I get back. I hope this is the cause of the problem. I'll get back on here as soon as I have changed it out.

[marrober9]

Do you now what part number that is or where I could buy a aftermarket replacement for it? I believe this is it but not sure since no picture available ACDELCO Part # 25649706

[Archon]

All Data shows the OEM part number as 12160947, and runs about $8.00. Could probably just get one from the dealer.

[marrober9]

Changed that part but it did nothing to the ac as a matter of fact it made the ac blow hot air out of the passenger vent now don't really know were to go from here maybe it's the ac control head idk. Any clues as to what might be causing this?

[bobgto65]

You can check the door position sensor signal in the wire going from the door actuator to the IPM, It is dark blue and goes to A6 on the IPM make sure there is continuity on this wire and the yellow one from the actuator to A12 on the IPM . measure the voltage across the blue wire open and closed and see if there is a gradual change. If not, then the actuator may be bad. Less likely since you replaced it. There is also an upper right air temperature sensor so replace that as well. I think you pull off the right side panel of the dash and it will be above the air duct/ Finally, you can also replace the IPM as this controls all of the functions of the AC modules.

[marrober9]

Would a Tech 2 scan help me out here?

[bobgto65]

I think that can perform diagnostic tests on the HVAC but the complete kit costs about 2 grand. Maybe it is worth paying the dealer to go through the diagnostics for a one hour fee.

[marrober9]

I finally got the problem fixed had to take it to an electrical shop. The ac control head and connector harness were repaired works perfect now.
Thanks for all the feed back.