I have posted on FChat about this but thought I would ask more local people.
I have lost the control over the air direction (feet / dash / demist) on my 355.
I bench tested the mixer motor (that moves the flap that controls the airflow) and it works fine, nice and smooth and quiet so it was pointing to the ECU being at fault.
I sent the ECU off to be repaired and they replaced the 6 drivers for the main functions and also 1 thermistor.
Thats now been re-installed and the air mixer direction is still not working. Further bench testing of the motor unit shows that it does seem to be ok, the readings from the potentiometer is within spec and does match up with the end stops. So its not likely to be the motor itself.
With the motor off the car the following happens. If you leave the motor all the way at one end stop when you ignition on the motor does a sweep and then parks.
Then if you move the position switch from say feet to demist the motor moves about 1/8th of a turn then bounces back to where it was. Almost like it is trying to move to the right spot then something happens it does not like and it returns to its spot. It does not matter which position you select it does the same.
So now I am looking at either a faulty switch on the HVAC panel or a wiring fault?
Dont suppose anyone in the NW has a spare HVAC panel I could test ? Its a 1 min job to swap them out.
Any one been through similar? TIA!
I have lost the control over the air direction (feet / dash / demist) on my 355.
I bench tested the mixer motor (that moves the flap that controls the airflow) and it works fine, nice and smooth and quiet so it was pointing to the ECU being at fault.
I sent the ECU off to be repaired and they replaced the 6 drivers for the main functions and also 1 thermistor.
Thats now been re-installed and the air mixer direction is still not working. Further bench testing of the motor unit shows that it does seem to be ok, the readings from the potentiometer is within spec and does match up with the end stops. So its not likely to be the motor itself.
With the motor off the car the following happens. If you leave the motor all the way at one end stop when you ignition on the motor does a sweep and then parks.
Then if you move the position switch from say feet to demist the motor moves about 1/8th of a turn then bounces back to where it was. Almost like it is trying to move to the right spot then something happens it does not like and it returns to its spot. It does not matter which position you select it does the same.
So now I am looking at either a faulty switch on the HVAC panel or a wiring fault?
Dont suppose anyone in the NW has a spare HVAC panel I could test ? Its a 1 min job to swap them out.
Any one been through similar? TIA!