RE: Wiper Diagnostics

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

I thought the same thing myself ... but as I told Tom in a direct
e-mail, the clue that the intermittent wipers seems to work exhonerates
the switch in the wiper mechanism ... my thinking is that the wiper
switch in the steering column has a problem ...

Steve Buchholz
San Jose, CA (USA)

> ----------
> If you take the motor apart, you'll find a large copper track covering
> around 150 degrees.  The way the motor works is that volts from the
> switch (interval or normal) start the motor running and the arm starts
> to move.  After a few degrees of movement, an internal wiper contacts
> the copper track.  Even if power is now removed from the switch, the
> motor will continue to move (powered via the copper track) until the
> internal wiper falls back off the end of the track - in the 'park'
> position.
> 
> Two things can happen:
> 
> a) The internal wiper becomes misregistered with respect to the
>    output spindle, locating the 'park' position 90 degrees out.
> 
> b) The copper track can wear through, especially in vehicles in
>    which the wipers have been used a _lot_ in interval mode on a
>    relatively dry windshield.
> 
> --
>  Phil Payne
>  phil@isham-research.demon.co.uk
>  Phone: +44 385302803  Fax: +44 1536723021
>  During Demon problems - copy critical mail to
> 100012.1660@compuserve.com
>