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Ghost wipers

 
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79porsche  



Joined: 12 Feb 2006
Posts: 36
Location: Greensboro, North Carolina

PostPosted: Fri Jan 05, 2007 2:17 am    Post subject: Ghost wipers Reply with quote

Test drove the car last night and suddenly the wipers sweeped across the windshield all on their own....I checked the switch lever and the wiper was in the off position. It was as if the switch was suddenly moved to "intermittent". I toggled the wiper lever switch several times but never could find a position where the wipers would completely stop sweeping.

Also...the wiper switch seems to have the following postions:

High -- Low -- Off -- Intermittent

However, even on the best days when the wipers don't have a mind of their own....the wiper motor never seems to not run in high speed....only low speed or intermittent.

Anybody seen this before? Is it the switch? Relay? or motor?

Thanks for the help!
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Lizard  



Joined: 03 Nov 2002
Posts: 9364
Location: Abbotsford BC. Canada

PostPosted: Fri Jan 05, 2007 2:35 am    Post subject: Reply with quote

you will need to clean/fix the ground to the steering column,

and the wiper arm is high, low, off, int.
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Smoothie  



Joined: 01 Jan 2003
Posts: 8032
Location: DE (the one near MD, PA, NJ)

PostPosted: Fri Jan 05, 2007 2:51 am    Post subject: Reply with quote

The wiper-turning-themselves-on is a grounding issue - ground for the wiper switch is completed through the screws that hold it on. The plate that the screws go through and make contact with is zinc plated. The zinc plating oxidises over time, degrading the ground. Then while driving, you hit a bump or make a turn and the conductivity through the ground changes, which signals the wiper relay to initiate a wipe. Quick fix (, but you'd have to go without the automatic wiper park and wash cycle) is to pull the relay. Better fix is to remove the steering wheel and clean just the spots behind the wiper switch mounting screws, then reinstall with toothed washers or/and dielectric grease to inhibit any more oxidation.
Also look here - http://www.924board.org/viewtopic.php?t=17996&start=03

The slow wiping problem can be oxisized connections anywhere from the switch - fuse/relay panel - wiper motor. I posted an easy test here - http://www.924board.org/viewtopic.php?t=17884 With that you can diagnose whether it's an internal motor problem or wiring/connections.
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968rz  



Joined: 21 Aug 2006
Posts: 537
Location: S. E. Wisconsin

PostPosted: Fri Jan 05, 2007 8:04 am    Post subject: Reply with quote

I had this same problem when I first got my 24. I went so far as to add a ground wire (small gauge) from the switch thru the column to a dash ground, never had a problem since (almost 10years)
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Rick
79 924 coupe Petrol Blue 3spd auto (wife's DD)
93 968 coupe Amazon Green 4spd Tip (my DD)
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Ozzie  



Joined: 12 Mar 2005
Posts: 4448
Location: Townsville, Qld. Australia

PostPosted: Fri Jan 05, 2007 8:15 am    Post subject: Reply with quote

Had similar problems but it was caused by the faulty wiring of the PO.
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Peter_in_AU  



Joined: 29 Jul 2001
Posts: 2745
Location: Sydney, Australia

PostPosted: Fri Jan 05, 2007 11:28 am    Post subject: Reply with quote

might also be worth having a read of this

http://www.924board.org/viewtopic.php?t=21013
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Lightning22  



Joined: 21 Sep 2006
Posts: 25
Location: UK

PostPosted: Mon Apr 16, 2007 9:07 pm    Post subject: Reply with quote

Smoothie wrote:
The wiper-turning-themselves-on is a grounding issue - ground for the wiper switch is completed through the screws that hold it on. The plate that the screws go through and make contact with is zinc plated. The zinc plating oxidises over time, degrading the ground. Then while driving, you hit a bump or make a turn and the conductivity through the ground changes, which signals the wiper relay to initiate a wipe. Quick fix (, but you'd have to go without the automatic wiper park and wash cycle) is to pull the relay. Better fix is to remove the steering wheel and clean just the spots behind the wiper switch mounting screws, then reinstall with toothed washers or/and dielectric grease to inhibit any more oxidation.
Also look here - http://www.924board.org/viewtopic.php?t=17996&start=03

The slow wiping problem can be oxisized connections anywhere from the switch - fuse/relay panel - wiper motor. I posted an easy test here - http://www.924board.org/viewtopic.php?t=17884 With that you can diagnose whether it's an internal motor problem or wiring/connections.



That advice has just saved me hours of work. Thank you.

Rich
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Mike924  



Joined: 12 Aug 2004
Posts: 2601
Location: IoW UK

PostPosted: Tue Apr 17, 2007 2:36 am    Post subject: Reply with quote

Ghost wipers in the sky...?
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