Heater Electrical Questions
 

Looking at the Bentley manual wiring diagram, in particular at the heat exchange sensor for an 86 which is connected to the heating control unit (between the seats) - it refers to the wire colour as NCA - what's NCA?

My heat exchange sensor is not connected to the plug in the auto heat control unit - in fact the plug has been cut off. I have found a used plug from a BMW and ground it down to fit. I was wondering if the orientation of the wires from the sensor to the plug matters?

The wire from the sensor is white with a heat protective coating and has a white and black wire inside. The heat exchange sensor is meant to tell the auto controller when the heat exchanger is up to temp, to allow the footwell blowers to function (currently mine do not).

Would this sensor simply be a normally open/closed switch - in which case the wire orientation on the plug should not matter. However, if the heat sensor increases or decreases resistance - will the orientation of the wires in the plug matter?

Any ideas from an electrical genius is welcomed.

Anyone?

An update...

Well it all works now, the footwell blowers are blowing for the first time, and the temp is being automatically controlled - as it should be.

However the footwell blowers seem to be distributing heat all the time, I may have those wires from the sensor about face - what do you think?

Thanks

From what you describe it sounds like you have the wire to the blowers connected to the hot side of the switch. Changing them around should fix the problem.

guessing NCA might be no color available, or something like that, a way to describe a wire like the one you describe, in a shielding or something where Porsche could not control the color.

Jim