9-3 aero 06 Heater Motor

[chris aka zaphod]

After 20 years of running Audi's, a work colleague bought an aero two week's ago - probably after seeing mine in the car park. 
So far, he is chuffed with it, but there is an issue with the blower motor coming full on when the car is started. The blower can be reduced in speed with the control buttons. I suggested that he check the SID settings, which he says he has.

Is there anything else that might cause the blower to come on full blast at start-up?

Thanks.

[sgould]

The fans will come on full if the system thinks that the internal temperature needs adjusting.  It may not be a fault of the fan motor, it may be a sensor fault.  Do the fans settle down?

[sgould]

Apart from the sensors, there is the motor control unit. this is fitted around the motor.  It's the bit the wires connect to and is bolted to the motor.

The motor is easily found, it's behind the glove box.  Take out the glove box and have a look.  Four screws at the front, one at the back, a connector and a hose.

[Petemate]

Same thing happens to mine, even if the aoircon is not selected, if I have set the temperature to 15 degrees or LO in a previous life (ie when I last used the car) I have set the fan to low speed via the control, but if the temp is set at 16 or above, the fan then starts up at the 2-bars. I just turned it down each time before cranking the engine up while I was putting on my seatbelt, if the temp was set low, but now it is colder the scenario does not occur.
HTH

[chris aka zaphod]

Thanks all. As an aside, where is the cabin sensor situated? Just curious!

[sgould]

I'm away at the moment so I can't check.  But I think the cabin sensor is in the roof console.  But there are other return air sensors under the dash.

[chris aka zaphod]

Thanks, Will.

[sgould]

OK...

The WIS says that there are 7 sensors

Cabin sensor - front of front centre roof console.
LH mixed air sensor - in the LH floor outlet of the heating and ventilation duct
RH mixed air sensor -  ditto in the RHS
LH mixed air - panel - in the air duct
RH mixed air - panel - in the air duct
Solar sensor on the dashboard
Outside air temp sensor - Centre of the black grille on the spoiler.