Windscreen wipers on a Polo faulty.
karlak - 29/12/11 at 10:09 AM
Not a Kit car, but my Sons Polo (03) 9n model.
For some reason both the wipers have decided to "park" themselves in a new position, about 5 inches further up the screen. They still do a
proper sweep cycle, but will always finish in the new position.
If I push the wipers back into place they will stay there, until I either restart the ignition, when they both go to the 5inches up the screen place,
or if I use the wipers, when they cycle and then stop in the new position.
I removed both wipers and placed them back where they should be, but then don't get a full cycle and hit the lower windscreen trim on the
downward sweep.
So how do these wipers know where they should stop? It seems the mechanism is just a type of cam arrangement - i am assuming the motor has some
cleverness in it? ( or not in the case of this one 
)
[Edited on 29/12/11 by karlak]
[Edited on 29/12/11 by karlak]
Danozeman - 29/12/11 at 10:18 AM
Sounds like the arms jumped round on the motor if its still doing the correct sweep. Take the scuttle trim off, slacked the nut off on the motor
where the arm fits and move the wiper blades to where they should sit and tighten the nut up. Job done. IIRC there should be a locating lug on there
where it should sit.
I bet hes operated them when frozen to the screen.
[Edited on 29/12/11 by Danozeman]
karlak - 29/12/11 at 10:40 AM
quote:
Originally posted by Danozeman
Sounds like the arms jumped round on the motor if its still doing the correct sweep. Take the scuttle trim off, slacked the nut off on the motor
where the arm fits and move the wiper blades to where they should sit and tighten the nut up. Job done. IIRC there should be a locating lug on there
where it should sit.
I bet hes operated them when frozen to the screen.
[Edited on 29/12/11 by Danozeman]
Nope, screen has not been frozen in the past week.
I have tried putting the blades where they should be - (did a typo on the above post). Should have said it Don't instead of Done for the full
sweep.
When repositioned - the cycle is 4 -5 inches short of getting to the A-pillar and then hits the lower screen trim on the downward sweep. before
finishing in the new wrong position about 5 inches higher than they should be.
Edited above post 
Madinventions - 29/12/11 at 12:01 PM
It may have bent/worn one of the internal electrical contact strips. For the price of a replacement motor, it's probably just worth replacing
it.
PSpirine - 29/12/11 at 01:47 PM
So they're sweeping correctly but parking in the wrong position (i.e. not at the very bottom of the cycle)
The usual cure is to replace the windscreen motor
Here's a link to a BMW forum which might help you understand what the problem could be: http://www.e90post.com/forums/showthread.php?t=459978
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However, once you've done all that you may as ewll have just swapped the wiper motor.
rusty nuts - 29/12/11 at 07:57 PM
Dan hit the nail on the head! Common problem
karlak - 30/12/11 at 01:18 PM
quote:
Originally posted by Madinventions
It may have bent/worn one of the internal electrical contact strips. For the price of a replacement motor, it's probably just worth replacing
it.
Yep, this was the problem, sort of.... - The sweep postition contacts were covered with Grease from the pinion screw. Cleaned it up, popped it back in
and all good again.. Cheers All
Also cleaned out the crap under the motor, was like compost so no water could drain away - How it hasnt rotted away is a miracle.. So two jobs done
for the price of one 