Heater Controls on a Porsche 968

Question

Hi all,
my heater works brilliantly! Better than any car I have ever had, hot by the end of the road, amazing... BUT, I can't get any air into the footwells, the slider control does nothing.The screen outlet is fine, but below, not a jot (except a bit of a water leak actually).

I have looked carefully, but cannot find where/how the air is deflected up or down. Any advice? Thanks.

Answer

Hi,
this is a common problem.
On the left hand side of the heater box(passenger footwell under the dash) you will see three servo motors. The upper one opens a flap to allow air onto the windscreen.

Move the upper slider and you will hear/see it move.

The middle one is the demist motor which will direct air at maximum speed to the windscreen and shuts off the other outlets. Press the demist button and you will see / hear it moving.

The one you are interested in is the lower one, this will move the footwell flap and direct air to the footwell, if it is working.

There are two solutions here. If you move the footwell slider on the heater control unit can you hear the motor moving?
If yes, then the connecting rod has popped out of its holder on the footwell flap rod and will need reinserting. Easily done if you take the glove box out (only 5 or 6 screws and the light).

Replace the small plastic clamp and also insert the small metal retaining piece to stop it popping out again.

If you do not hear the motor moving then it has seized ( a common problem as it seems if there is a leak it drips on to this servo which rusts). Relatively easy to remove (if a little fiddly) and replace with a working secondhand unit. Connect it up and make sure it works before screwing back together.

Hey presto...heat to your feet

(Tall Phil)