89 964 Heat Issue

[andrewdoak]

I've been through the board trying to find my specific issue, and haven't benn able to find it, so I ask those of you that may have a solution.

I've checked and adjusted my servos (they work).
Replaced my rear fan motor (and it's working).
Replaced relay (not the problem).
Checked all fuses (all good).

PROBLEM: no heat.

I turn the temp dial to blue and I can blast cold air till I freeze. I can turn on the AC and it's now really frosty. One tick towards the red dot and all fans shut off. Defrost no longer blasts air (nothing). Nothing is blowing once I turn the dial off of blue. Defrost doesn't work when on blue.

I've got the blow-out illustration from Porsche and it appears there is a "blower interior sensor" part number 964 659 148 00 (2 in attached) which is behind the dials. Anyone found this to be the culprit? Something else? I'm freaking freezing here.

Thanks for the help.

**if my symptoms/solutions are in another thread, please, by all means point me over. my apologies for not finding it on my own.**

[lucittm]

I think #2 above just samples the air. Your problem sounds more like a logic issue. If you turn the dial and all the fans stop, the problem lies behind the dial. If you can get a donor HVAC control unit, that would be a quick test. If it is bad, I think there are some on ebay right now.

Mark

[andrewdoak]

thanks for the reply Mark.