Porsche Enthusiasts Club Forum

Im having a wee problem with my heater in my 89' s2.

Basically it keeps blowing hot then cold then hot then cold and so on. It doesnt seem to matter where i have the control set it does the same thing.

Any ideas?

cheers

stev

Hi Stev.
I'd go for the switch to start off with

Daz.

Sorry to recall an old issue but I have the same problem on my 91 S2. Has anyone found a solution to this one?

Steve

Hi

i still havent rectified the problem yet. I replaced the switch unit with one from a breakers and it hasnt made any difference.

I havent had time to have a good look around yet to find the problem.

does anyone have anymore suggestions???

stev

The heater control valve is vacuum operated, so it may be a good idea to check the pipes for leaks.

The pipes are a bugger for splitting or coming off the heater unit too.

The automatic temperature unit is controlled by three temperature sensors around the car, if one of them fails then the system cannot regulate temperature properly.

1. One is under the bonnet directly above the steering wheel where air is sucked into the system, it measures the outside temperature. Mine failed and caused the heater to blow cold all the time. A new sensor was about £15 IIRC

2. One is behind the tiny grille next to the cigarette lighter. There is a flexi tube (which can come undone) and the sensor is at the end of it behind the glovebox liner. This senses the temperature inside the car.

3. One is behind the central twin vents in the middle of the dashboard. It senses the air/heater mixture.

There is a lot of info and pictures at http://www.clarks-garage.com specifically at http://www.clarks-garage.com/shop-manual/hvac-01.htm