How to avoid the clicking ventilator flap

The trick is to make the turning momentum of the ventilator motor weak
when it reaches the end of it's movement. One way of doing this is of course
to mount some kind of micro switch that cuts the power. This would be a
mechanical challenge and also would be difficult to fit in.

I have with great success managed to limit the momentum with an electrical
circuit. It is really cheap and has few components:

You will need the following

• LM317T adjustable voltage stabilizer
• 10 ohm resistor
• A piece of circuit board to solder on

This is the pin out of the LM317 T. It is an adjustable voltage limiter
but now we're going to use it to limit current instead...

This is the coupling. I used the Vout in the radiator fin, that's why the
center pin is cut below.

This picture shows were to connect the circuit. The PCB shown is the one
behind the defroster/recirculate buttons (this one is without air-condition).
Please note the cut, remember, you DO want the current to go through the
limiter...

Also, the point of connection is much easier on the component side of the
PCB, the picture only shows where in the circuit you must be attached.

This schematic shows the same as the picture (this one, however, is
equipped with AC). Since the flap motor is governed by switching the
polarity we must connect before the outlet. This simplifies the current
limiter substantially