Testing 4k - 5k window switches

[E Bavely]

Hello all...

As I've learned on this list, other than door handles (go team DH!), it
seems like items like window switches on 4k's and 5k's are often prone to
failure.

Being proactive and slightly looney about having spares, I picked up a bunch
of spare window switches for a 86 4kcsq at a local junkyard.  I had no idea
if these switches are any good (they were cheap), so I wanted to test them.

With the help of an engineer at work, we used a voltmeter and schematic to
test the resistance (function) of the switches in various positions.  A few
turned out to be bad, while others tested ok or at least "made" acceptable
connections when we looked at the amount of resistance on the voltmeter.

The strange part is that when I took the supposedly "good" switches and put
them in the car, they did not work as they should have.  Some would only
work the window in one direction, others were flakey in general.

I used a known good switch as a control, so I hopefully eliminated the
possibility of having faulty wiring/motors in the doors. I figured that even
though they tested fine, maybe some of the switches did not allow enough
current to pass through and actuate the motors.

Also, in the process, I managed to break one of the plugs for the switch in
the 4kcsq and hacked up my fingers pretty badly trying to wedge my hand in
the console to change plugs/switches five times.

So here's the point:  I was wondering if it would be possible it to make
some kind of test harness for this type of window switch (4k and some 5k).
I have an extra plug/wire assembly from a similar car.  My plan was to just
use male spade connectors, longer wires and "piggy back" into the existing
plug that's in the car.  That way, I could connect into the plug in question
with more working room and change switches at will.

I'm not sure if this will work...one concern is the one wire that is
actually connected to two places on the back of the plug.  I'm not sure what
extending the wires and adding another set of wires/plugs will do to that
wire and/or the accuracy of the test.

A friend suggested rigging up a test harness using a car battery or power
source, the plug end and then some kind of two-way motor or resistor for
load on the switch.  Maybe I'm overlooking something or making this too
tough...

Has this been done before?  Any suggestions?  Easier ways to test switches?
I probably have 10 or so switches now...it'd be nice to have a pile of known
good ones to swap out instead of trying to fight with that tight quarters
wiring...

Thanks in advance...Sorry the post is so long...

Elliott Bavely

86 4000CS Quattro
83 GTI FSP Racey car
83 GTI 16V
90 Cabriolet


_________________________________________________________________
Chat with friends online, try MSN Messenger: http://messenger.msn.com