Re: Re: [Chrysler300] Subject: Electric Window Motors

[whuff <whuff@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Hi Jim,

Over the years I have read several articles on this subject.  This 
link probably is the best one. I found it tonight on line, Rich 
Ebooger as he is sometimes known writes for one of the MOPAR mags and 
is quite knowledgeable.

http://www.allpar.com/history/mopar/electrical.html

Basically there are two approaches.  One eliminates the large current 
through the interior of the car and uses a voltmeter to monitor 
battery/charging condition.  A large fused wire is run from a battery 
connection to the alternator positive post to carry charging (or 
discharging) current.That reflects a more modern way of thinking, you 
just don't see many ammeters in cars these days.  Of course, in your 
beloved MOPAR, the amp gauge would not work, it would just sit there, 
and a voltmeter would have to be mounted somewhere.  A problem with 
this method other than lack of original dash workings is that some 
cars may take power from one of the ammeter posts, particularly the 
forward look cars.  Later in the 60's and early 70's I think some 
voltage limiters might have been mounted to one of the posts, 
especially those cars that may have had a handful of wires behind the 
dash rather than full circuit boards.  An easy fix would be to leave 
the ammeter wire from the battery source in place, so voltage would 
be available but with only one wire no charging current would flow.

The second approach would involve keeping the charging current 
flowing through the ammeter, which is a really tough and durable 
instrument, but eliminating the trouble prone bulkhead 
connectors.  This means routing a large wire (#10 or even #8) through 
the bulkhead using a rubber grommet, i.e. no connector to the ammeter 
and then back through the grommet to the engine compartment.  This 
would actually be my choice if an original appearance is desired, and 
it is the easiest to perform as long as you can stand on your head 
with your reading glasses on upside down to see what your doing under the dash.

A third method which just ain't worth the time and trouble for me is 
to remove the shunt from the back of the ammeter and fit an external 
shunt somewhere it he engine compartment. The shunt is the large 
metal piece that actually carries the charging current, which does 
not go through the gauge mechanism itself.   Then small wires could 
be run to the ammeter from each end of the shunt.  All ammeters 
actually function as a voltmeter reading the voltage drop across 
either an external or internal shunt.  This sounds like a good idea 
until you start to try and calculate the shunt value and the 
resistance of the connecting wires.  Its all in the tenths or maybe 
hundredths of ohms.  Each connection adds some resistance.  Unless 
you just wanted an indication of charge or discharge, this method 
would take a lot of try and try again cutting and splicing of wires 
and changing shunt values to get anywhere near accurate readings.  It 
is the most elegant method, I think, just a lot of trouble.

If I haven't hopelessly confused you by now I am losing my 
touch.  :-D  Good luck.

Bill Huff


At 12/1/200608:10 PM, fabe7445@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx wrote:
>    Bill,
>
>   Do you have the info or link on how to eliminate the ammeter from 
> our Mopars ?
>
>   Thanks, Jim Faber