Advice please - Coupe GT rear wiper motor

86audicoupe · 01-09-19, 06:20 AM

Hi all

Latest job to tackle...rear wiper motor isn’t working. What are the common causes of failure? I’ve checked the obvious (relay and fuse). I’m assuming the best way to access it is by taking out the rear seat and rear shelf?

Thanks

Isimmo · 01-09-19, 09:50 AM

Before you do, drench the column switches in contact cleaner. Then if no joy.

It’s back seat out, speakers out, remove parcels shelf. Couple of points to note, if it has not been out before, try to avoid stirring up the decades of dust or wear a mask as the foam on the back can also break down.

Then voltage test the wiring.

If the wiring is fine, the motor has died.

SwallownAmazon · 01-09-19, 10:08 AM

One more point, if as Ian suggests the motor has died, don't leave it switched on for any length of time with the ignition on. My B3 had been left under a car cover outside for several years and the wiper motor had seized up through lack of use. When it was being tested, the wiring got VERY hot, old PVC insulation loses its flexibility and overheating it will exacerbate the problem.

86audicoupe · 10-09-19, 12:53 PM

Hi chaps

Thanks for your reply and advice on this. I’ll go through your suggestions and report back

BackintheFold · 10-09-19, 01:04 PM

i've found many seize up because of rust in the spindle.
If you have someone operate the wiper, and then manually assist the blade and find that it does work (you will feel the motor try to help) then you can remove it all, clean the motor and spindle, regrease (to keep water out of the spindle) and reassemble

I've done it more times than I remember (at least 4)

mikes2 · 10-09-19, 02:13 PM

I've got a couple of these lying around doing nothing.

Let me know if you need one

20vcqdriver · 10-09-19, 08:33 PM

Quote:

Originally Posted by BackintheFold

i've found many seize up because of rust in the spindle.
If you have someone operate the wiper, and then manually assist the blade and find that it does work (you will feel the motor try to help) then you can remove it all, clean the motor and spindle, regrease (to keep water out of the spindle) and reassemble

I've done it more times than I remember (at least 4)

Ditto, done this twice on mine and still going though I expect the next time it will need new brushes too

...

01-09-19, 09:50 AM	#2
Isimmo Super Moderator Classic Audi Club Member Join Date: Jul 2007 Location: Sissix-by-the-sea Posts: 15,218	Before you do, drench the column switches in contact cleaner. Then if no joy. It’s back seat out, speakers out, remove parcels shelf. Couple of points to note, if it has not been out before, try to avoid stirring up the decades of dust or wear a mask as the foam on the back can also break down. Then voltage test the wiring. If the wiring is fine, the motor has died. __________________ 1985 WR quattro, 1985 20vT RallyRep, 1993 MTM ABY S2 Avant. 2010 S3 Sportback.

10-09-19, 02:13 PM	#6
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	I've got a couple of these lying around doing nothing. Let me know if you need one __________________ 1991 90 quattro 20v sport 1991 90 quattro

01-09-19, 10:08 AM	#3
SwallownAmazon Grown up member Classic Audi Club Member Join Date: Jun 2017 Location: Tonbridge, Kent Posts: 511	One more point, if as Ian suggests the motor has died, don't leave it switched on for any length of time with the ignition on. My B3 had been left under a car cover outside for several years and the wiper motor had seized up through lack of use. When it was being tested, the wiring got VERY hot, old PVC insulation loses its flexibility and overheating it will exacerbate the problem.

10-09-19, 12:53 PM	#4
86audicoupe Classic Audi Pervert! Classic Audi Club Member Join Date: Dec 2007 Location: Dorset Posts: 2,182	Hi chaps Thanks for your reply and advice on this. I’ll go through your suggestions and report back

10-09-19, 01:04 PM	#5
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,171	i've found many seize up because of rust in the spindle. If you have someone operate the wiper, and then manually assist the blade and find that it does work (you will feel the motor try to help) then you can remove it all, clean the motor and spindle, regrease (to keep water out of the spindle) and reassemble I've done it more times than I remember (at least 4)