I'm working on a 2001 A4 TDi and the blower is intermittant now it works less than it works. I've tried a different motor off ebay but this has the same fault?
Turn on climate control to auto or any other setting and plug the unit in and it works for a few seconds then stops. If you remove and motor plug it in again straight away it may work again but for less time. This is the same on both motors. If you leave the unit installed as it should be it will not work after the first install.
I've checked power and earth and both are good. Also with a scope I've got data going to the blower on the Brown/black wire which changes when you change the fan speed, but on the yellow wire which I think is the motor return, when the fan is running for its short period you have data. This waveform is slightly distorted with a slopping front egde, and as soon as the motor stops you lose this data.
This is a later motor with a 8E2 prefix part number so no brushes to replace.
I've noticed quite a few people having intermittant A/C which comes and goes,
PLease can someone confirm that the fault is the motor itself or should I look else where.
Thanks