CCUs and servos

[# 37]

OK so i've been reading a lot on this subject.
Found myself a donor system from a race car-to-be so i have spare servos, fans etc..

This is the problem:
when the car is started the fresh air flap is closed.
Turning the fan knob on the CCU gets nothing. No fan motor noise, no blowing, nada.
Upon hitting defrost- also nothing.
All servos are not moving.

As i understand it, when the motor is first started and when it is shut off, the fresh air servo closes the vent completely.
Then, as you regulate the thermostat and the fan motor setting, the servo opens the vents, and routes to
either side mixing servos.

Question is this: does it sound like the fan that is built into the body of the CCU is dead?
And can i replace this fan without buying a new CCU?

[Steve]

I'm not an expert on these Climate Control systems so I'm counting on someone ringing in here to help.

[Tom]

The fan built into the servo unit is only for moving air across its own internal temp sensor. It sounds like you have issues with the fan resistors or relays. There is a relationship with the booster fan in the engine compartment.

ToreB is just crazy knowledgable. Have a look here.

www.porschehvac.bergvill.com

[# 37]

[# 37]

Resolution - Epilogue.
I replaced the center fresh air servo and the left (driver) mixing servo.
Fuse #1 was blown- 30 amp.

When the servos got worse and failed, they must have created an increase in current = heat and overloaded
the circuit. Luckily not damaging the CCU.
Everything works as it should now and i will wait for the next exciting chapter.

Thanks all for inputs and advice

Nic