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A/C Heater temperature control problem. Please help.

Hey guys. I'm stumped.

My A/C works great, the heater works great, the blower works, recirculate works, all modes work. BUT, when you change the temperature control from anything but full cold, it goes to full hot. There's no middle ground, it's annoying.

I've read up as much as I could, checked the wiring diagrams and thought I had isolated the problem. According to the wiring diagram the temperature is controlled and regulated directly by the knob mounted on the dash. The temp is adjusted by two actuators mounted on the HVAC module under the stereo.

At first I thought that maybe one of the actuators was bad because it wasn't moving when i changed the temperature. But when I recalibrated the controls (by holding down the A/C and defrost buttons until the lights blink) i saw that both actuators were moving freely... so I determined that it must be the control module...

So I bought a new one ($100), it came in today, I installed it... problem is still there... I'm frustrated.

Has anyone had this problem? Does anyone know the solution?

Please help. Thanks.

Sorry, I can't help with your problem, but, I am interested in knowing how you learned the 'recalibration' trick, and exactly what does it recalibrate? Thx:)

I have the same problem with my '07. I'm taking it to the dealer in a couple weeks to get that and a couple other warranty items fixed. I'll post my findings when I know something else.

Quote:

Originally Posted by supsam86 (Post 233106)

Where did you get the control unit for $100? It is the one with the 3 knobs correct?

Thanks

Hooty-Hoo: Any news on this?

Willie: Ebay, they've got everything. Yeah, three knobs that mount below the stereo. I'll sell it to you for 100 if you want. I was about to list it on ebay because obviously thats not my problem.

Quote:

Originally Posted by supsam86 (Post 233899)

Is it a new complete control unit? One of my LEDs went out but other than than it works fine....

Yes, it's a complete unit with the three knobs. It will be on eBay as of tonight.

Quote:

Originally Posted by supsam86 (Post 235619)

Yes, it's a complete unit with the three knobs. It will be on eBay as of tonight.

Repeat question: Where did you learn the 'recalibration' trick, and what does it recalibrate? thx

I don't really know where i learned about the recalibration thing. I'm not really sure what it does either, but I know it tests all functions of the HVAC system (checks mode actuators and temp actuators.) I'm pretty sure you have to have all the dials all the way to the right and then hold the AC and Defrost buttons at the same time until all the lights start blinking. The same thing happens if you disconnect the battery.

by the way, this problem disappeared yesterday when it was really cold in the morning, my temp control works fine now. I'm assuming that one of the two temp control doors was stuck and it just needed to break free. I haven't taken it apart to find out for sure.