Re: 89 100 Wagon charging system woes :-(

[DeWitt Harrison <de@aztek-eng.com>]

On Wed, 20 Aug 1997 08:57:35 -0400, Mike LaRosa wrote:

>Thanks Scott, Tony and Katpassage...
>
>I'll check thru your suggestions tonight and check back :-)
>
>Although, the cables didn't have any nasty green goo
>on either the starter end or battery end.  
>
>Is the positive cable that goes from the starter to the battery
>a straight thru cable ? or is there another connector or lug
>along the way ?  anybody know ?

On many cars, there is a heavy duty crimped connection in this
cable run located somewhere under the carpet pad on the firewall
on the passenger's side.  If this connection is poor enough, the crimp
can actually feel warm to the touch. Other potential trouble spots: the
battery to chassis ground connection and the engine to chassis
ground strap connections as noted by Scott.

>Scott, I'm using a sunpro 7680 or some number like that :-)
>it has ac, dc, ohms, dwell, and tach for a 5cyl on it.  The
>ohm dial has 200k, 20k, 2k and a tone setting.  The number
>it showed was 0.000.  I did touch them together before I 
>ohmed anything out and they said 0.000.  Is this what you were
>looking for ?

The units of resistance are in kilo-ohms. The least significant
digit on  your readout represents 1 ohm increments. But it would
only require 0.05 ohms of resistance to drop 1.5 volts at a 30A
load, as an example. To confirm your suspicion about the alternator
to battery +terminal run, directly measure the voltage difference
between those two points while the cooling fan is running, etc.
You really shouldn't ever see even as much as a half volt differential
end to end if everything is clean and tight. Recall that this same
run must supply starter motor current. On the other hand,
other wiring in the car is of much smaller diameter and can
drop a volt or more in the high amp circuits (lights, high fan, etc.).

DeWitt Harrison   de@aztek-eng.com
Boulder, CO
88 5kcstq