Heater Blower Motor / resistor

Blueirv · 24-10-2010,04:36 PM

Hi
I know there are various posts concerning heater blower motor problems and many refer to the need to replace a resistor.
How do I know if the problem is the resistor or if it is the motor itself?
I have removed the glove box and the motor and I cannot see a separate resistor - is it integral?
Audi A4 Avant 1997 2.8 SE with climate control.
Thanks
Alex

**Alan02** · 25-10-2010,07:56 PM

Since you have Climate Control, the fan is controlled by that. Without, and you will have a Resistor. If the motor isn`t running try a direct power supply to motor. This will give you an idea where problem lies.

Blueirv · 26-10-2010,10:59 AM

Hi Alan
I have now done this and the motor is running.
If it's not the resistor or the motor any ideas what else it might be?
Thanks
Alex

**Crasher** · 26-10-2010,11:03 AM

If the motor stops and starts and often comes to life again after going over a bump, the brushes are worn and need replacing or fit a new motor,

Blueirv · 26-10-2010,11:09 AM

Thanks
The motor wasn't running at all. I removed it from the car and attached it to a DC supply and it runs fine. Could this still be the brushes?

**bannedbiker** · 26-10-2010,11:52 AM

Originally Posted by Blueirv

Thanks
The motor wasn't running at all. I removed it from the car and attached it to a DC supply and it runs fine. Could this still be the brushes?

Unlikely. If you've got any sort of meter check and see if the motor is being supplied power when it's installed.

Blueirv · 26-10-2010,12:16 PM

I've now reattached the motor to the car after testing and it is currently running OK.
This may indicate that it is indeed an intermittent problem and could be down to the brushes.
The unit is sealed and it is difficult to actually get to the motor to replace the brushes.
It is part number 8D2820021 and it looks like this:

**rob_a4** · 29-10-2010,10:52 AM

hi, the motor isnt sealed, there are 3 rubber bungs
press these in and down and the lot will seperate.

then release the two clips holding the springs that hold the brushes
unsolder the old brushes, fit new brushes and solder in place.

re fit

job done

**Axios** · 29-10-2010,11:13 AM

Originally Posted by rob_a4

hi, the motor isnt sealed, there are 3 rubber bungs
press these in and down and the lot will seperate.

then release the two clips holding the springs that hold the brushes
unsolder the old brushes, fit new brushes and solder in place.

re fit

job done

I got some pictures of this if it will help any one out in the future.

Blueirv · 29-10-2010,05:13 PM

Thanks all who offered advice. Bought brushes from eBay and replaced them in about 30 mins. Blower working perfectly and at the cost of a tenner. If I can help any others let me know.
Alex