[V8] Heat related issues....GM climate control silliness....

[Ted Haug]

More questions for the collective experts.

Well the saga continues in my quest to restore a more temperate environment in the cabin of the V8.  Here's a run down on what we know, and what I think the problem might be:

Heater is clean, good flow.  Thermostat is replaced and works perfectly, car comes up to operating temperature quite nicely.  What doesn't work:  the blend door motor/actuator is not moving the flaps to direct the air flow across the heater core.  Channel 7 in the on board diagnostics has that rudimentary graphic that shows the blend door to be set to warm, but that segment is flashing and as it flashes, there is a corresponding click from the controller behind the glove box.  I have removed the actuator from the box in the cowl, so I could see if it is moving as the temperature on control panel in the dash is adjusted.  It does not move.  It will move if I take it over to the work bench and apply 12v to the harness.  

I did try another control panel, as I have a couple of spares and the system operated the same way.  So, I think the blend door actuator is the issue....even though I can make the motor move, the controller behind the glove box cannot.  And I think that is because it can't see where the motor is positioned in it's cycle.  Thoughts?

My second possibility would be the controller behind the glove box is having an issue.  But it seems to be working well other wise, and is running it's vacuum solenoids to adjust the airflow from the windscreen and floor to the center vents as the temp is adjusted.

I also replace the vacuum line to the fresh air flap plenum...just because I really like getting my hands contorted in ways that they humanly should not be able to.

I am hoping someone may have run into a similar situation and may be able to say without question that the problem is definitely ___________________ (fill in the blank).

Thanks again to all for your time and advice.  Looks like I may be heading out to the junk yard tomorrow and it is to be a balmy 24 degrees here in Central PA.  Thank goodness for my 1982 4000 4E that has a great heater and still gets 30+ mpg no matter how I drive her.....and she doesn't have a silly General Motors climate control system....give me a lever actuated bowden cable any day over this electronic horse sh!t.

Cheers,

Ted H.

1982 4000 4E
1986 Coupe GT
1990 V8 quattro