Re: EE's needed for washer problem

[FBFISH@aol.com]

In a message dated 2/14/99 1:10:20 PM Eastern Standard Time, qcar@hotmail.com
writes:

<<  I have 12v 
 where the plug goes into the pump when I pull back the windshield wiper 
 stalk; if I run 12v direct from my battery to the the pump, the pump 
 whirs happily.  Yet when I plug it in and pull the stalk back, nothing 
 will happen.  The windshield wipers do not even go back and forth.  When 
 I unplug the pump and pull the stalk back, the wipers go just fine.   >>

Matt- Without a schematic its difficult to say with certainty. From your
description, I would offer the following. First, you do not say, but I assume
the plug you have disconnected is two pronged ( one for +, one for - ). Two
things come to mind: when you make the check upstream of the pump, with the
plug disconnected, you are measuring an open circuit voltage. This means there
is continuity, but doesn't tell you anything about the quality of the
wire/connection (could be poor,lots of resistance). With pump current this
could lower the voltage not only to the pump, but also to the wiper motor. If
this is the case, a review of the schematics will tell you where to look for
the bad connection. It will be upstream of where the two devices draw power.
The other possibility is similiar, but concerns the ground or return path. You
do not say how you provided ground when you powered the pump directly from 12
V. If you supplied an external ground, it could imply a bad return circuit
upstream of the pump. This could also explain the lack of wiper motor
operation but only if the bad return is common to both the pump and the wiper
motor. I consider this less likely. If I had to guess, I would pick the stalk
switch as the culprit.` Having said that I am a firm believer in thorough
trouble shooting, not a series of remove and replace actions. HTH
Frank Santoro
1990 V8 for sale
1998 A8