964 heater control problem
 

Hi,

The only way to have some heat in my 1990 964 is to turn the knob completely to the right (max) on the heater control in dash. Even on cold mornings (55F), no heat with the knob set to 24C (80F).

I tried an other heater control unit and it worked OK.
I also tried to replaced just the front of the heater controller with the front of the working control unit (all buttons and thermostat) and still no heat , so it seems to be inside the heater control box.

Where can I have it tested and repaired? Vertex have some for 1299$ !!! Gulp!

Thanks to everybody.

No real way to repair them that I know of, other than to take it apart and look for bad traces\burned components.

sorry

AFJ

You may want to check your servos, before looking at the control unit itself. There's a good writeup here...

http://www.porsche964.co.uk/technical/servos.htm

That's where I'd look first. I had to replace a couple of servos on mine after freezing my way through my first winter with my car.

I don't know him or have any affiliation with him, but I believe Loren repairs these. His Pelican user id is Lorenfb. I believe this is his website...

www.systemsc.com

Maybe someone else can give you more options.

Jason

Heater problem

I had a similar problem with no air blowing and I narrowed the blem down to the rear blower was bad in the engine compartment. If there is no air pressure to the servos from the rear blower then the twin cabin blowers will not come on.

This option should be the first item checked or everything else down stream will not function.

Good luck

Will you front fans run (with the switch) when the temp switch is on the blue dot? If yes, then I would definitely check out the rear fan.