AC Oddity

[n5yzv]

I recently became a 2007 Tahoe LT 4WD owner. Thus far, I love it.

I am having an oddity with the AC/Blower.

I cannot adjust the temp on either driver or passenger side. I also cannot direct the flow. At the moment, it is cold and blows out the "front" vents.

I have seen some similar on the forums, but not both sides and both temp and direction of the flow. Suggestions?

Thanks an advance!

Mark

 

[OR VietVet]

Have seen where you can unhook the battery for about 5-10 minutes and it will reset the BCM that controls that. Not always but lots of times on here it works.

 

[n5yzv]

That's a good idea. I'll do that tomorrow AM.

Thanks!

 

[OR VietVet]

Let us know and then we can go from there.

 

[n5yzv]

I disconnected the battery for about 45 min. Reconnected and it has the same symptom. Cold air only (no diffusing to heat on either driver or passenger side) and only air to the front vents, no defrost or feet.

Oddly when I direct the air to defrost, the sound changes of the blower, but no air flow difference to anything.

 

[OR VietVet]

Ok. Now do a search here about blend door actuators and BCM controllers. There is lots of related threads about this. You will likely find one where the same problems were happening and what was done to fix it.

 

[n5yzv]

Thanks,
searching....

 

[n5yzv]

Well, I have been digging around. Here is a bit more of the problem at hand:
-I cannot adjust the temp on either side.
-I cannot adjust the air output to defrost, dash or floor (only dash)
-I cannot adjust recirculate or fresh

I can:
-adjust the fan speed
-turn the AC compressor on/off
-turn the rear unit on/off
-turn on the rear defrost

The best I can figure out, is that my HVAC Control Panel is malfunctioning. I can find a replacement on Amazon ( http://goo.gl/ltByLd ). I am tempted to just order and swap, return if it doesn't help. What do you think?

If it isn't this, I think it is "BCM Land".

Thanks!

Mark

 

[n5yzv]

So the fun continues. After resetting the BCM, I decided to try to reset the connection on the AC Panel in the dash, after reading a few that noted success with this. Nope. So, I purchased a new replacement for it. Nope.

So again, here are the symptoms:
1. No defrost
2. No floor
3. No heat (both sides)
4. No Recirculate Air

What is working:
1. AC is cold! (yeah! I'm in Texas!)
2. Cold Air to Dash (See ^^^)
3. Rear unit control is fine. Heat, cool, fan, all works.

What I have done:
1. I have reset the BCM.
2. I have reconnected the AC Control Head
3. I have replaced the AC Control Head.

Ideas?

Thanks!