henrys964

thanks very much Tore
will begin the ccu work this weekend also check the ccu fan as well, as the Air conditioner ,is working great here in the caribbean weather, the only thing is that ac condenser fan staying on , I already check the connections in the fan and I see some connections with black tape , will check that out with the diagrams and put it in original state I think somebody put a ignition positive direct to the fan also will check that out

about your page I studied it since I bought the car and is very well detailed it help me a lot in understanding the system

thanks again
will keep you informed

henry

henrys964

do the transistor change and by now no battery drain and ccu working fine , is turning off with the ignition turning off

now working in the other proyect ( back spoiler ) issue advice will be appreciated

thanks very much for your help

ToreB

Great news! I am glad to be at help.
What is the problem with your spoiler?
Cheers,
Tore

henrys964

The spoiler was in continious running in down position until I check in other post that it was the same transistor as the ccu in the spoiler control I change all bc 337 in control , no more in the down position but isnt doing anything right now. The spoiler light in the clock still on, I take out the module and the light off
check everything mecanically and working good , the microswitches working good.

any advice
thanks

Zingari

How long is the CCU fan supposed to run after the ignition is turned off? I'm sure mine can run for up to 15mins?

ToreB

The CCU can stay on up to 20 minutes after ignition off. The CCU fan will run in this period, as well as any needed cooling action of the rear fan.
Cheers,

jorijori

Hi Tore,

I have a question too, my AC is blowing cold air through the center vents (good) and the footwell (no need). When I try to select the levers so all cold air blow through center vents, nothing happen. What is wrong with the CCU?

Note, when I ran the scantool there was error code which I cleared. After a while it will come back. Don't know cause the error code.

TIA

ToreB

Hi jorijori, you could run my DIY test for checking the ventilation servos: www.porschehvac.bergvill.com
What is the error code number?
Cheers,
Tore

RickyTerzis

Hi...i am a new user here. As per my knowledge the AUX fan in the engine compartment should start at low speed, then go to high as you turn the temperature **** up. This is done to boost the heated air flow. Ask a classic beetle owner why we need booster fans.There's a feedback line to the CCU from the AUX fan for fan operation supervision. If the fan motor, low speed resistor or the fuse fails the CCU will shut down the front fans as soon as the rear blower is needed.

ToreB

Welcome to the forum.
Your statement is not entirely correct. The rear fan speed depend on the CCU fan speed setting, not the temperature setting.
This is easily shown by setting the temperature and fan settings to minimum, the rear fan shall not run. (provided the engine is cold) Then set to max temperature, the rear fan shall start on low speed. Set to fan speed 2 or above, and the rear fan shall run on full speed.
You are correct, the CCU supervises the rear fan, and switches to full speed if the low speed does not work. (mostly due to a defective resistor) The CCU will also slow down or shut off the two front blowers when detecting a fault in the rear fan circuit.
Cheers,
Tore