(ET) traced the Hot short to the frame

["Rhett T. George" <rtg ee duke edu>]

 - Greetings -

Bill from Maine has uncovered yet another mystery circuit which pops
up as folks thru the years add on to a utilitarian device.  Windshield
wiper and cigarette lighter additions to cars, trucks, boats, and 
Elec-Traks have introduced surprising behavior.  As I read Bill's
description of finding the hot short, I understand that he is describing
the windshield wiper motor, not the traction motor.  I believe that
it may run from the 36 volt circuit which is energized when the power
connect switch is engaged.

I imagine that the wiper is connected to a wiper off-on switch which 
may be in the ground side of the wiper motor circuit.  This is done
so that the motor will park the blade at one end of the swing, putting
it out of vision's way.  If in connecting the return circuit to the 
wiper housing, the switch was bypassed, indeed the wiper will run 
whenever the power connect contactor is engaged.  This is certainly
true with autos and boats I have worked on.

Bill, good luck on locating the wiper return terminal and, maybe,
still another short.  One suggestion is to mount the wiper mechanism
to the cab with insulating washers.

Keep on Trakin'
                                        Rhett George