Bill Kohnke

The mixing flap on the pass(right) side goes to full closed and stays there. I have taken it apart and cleaned the tracks, checked the motor(it's ok) but when plugged into the harness, it always goes to full closed even if I use 12v to get it full or partially open first.
The other side works in harmony with the Auto a/c control from warm to cold no problem.
I plugged the flap's connector into the defroster flap control unit and it goes to full closed the same as the mixing flap.
somewhere I saw a reference to temp sensors left and right in the wiring somewhere.
Where might I find them and can they be replaced?
I have a 1989 C4 early with no air bags and the durametric can't see the ac to test anything.
I rebuilt the top-end last winter and the floor is still dry 4,000 miles later, so I'm waiting for the where and when of the 1st drops of oil.
Any suggestions to getting the right side to modulate temps?
Thank you
Bill Kohnke

ToreB

This might be due to a defective right mixer chamber sensor. This is a 10kOhm NTC placed in a plastic stalk, placed on top of the mixer chamber. The sensors are easy to get to, they are available under the plastic cover under the windscreen in the trunk. The replacement part from Porsche is a complete wiring harness for this particular spot, but it is a 10 minute job to solder a new NTC in the existing plastic stalk.
See this thread for a couple of pics of the sensor, see below pic, items 47.
Cheers,
Tore

Bill Kohnke

Perfect I replaced the Thermisterand now both sides have heat.
less than $2 at the electronics store versus $196.00 porsche repair part.
Bought a robot arm for my grandson and I to put together at the store while I was there and I still came out ahead.
Thank You
Bill

ToreB

Great news! Thank you for informing us.
Cheers,
Tore