If you look closely at the Bentley, you will see, I think, that it
shows that the solenoid has two coils, one which goes to ground thru
the housing and the other which is grounded thru the starter circuit
itself.  I believe that this means that if the starter brushes, etc.
are bad enough, the solenoid will not activate, with a relay or not.
The short cable that leads from the solenoid into the starter body is
part of this circuit.  When the starter on my '91 GL quit, it was
because that cable had turned to dust.  Those very thin strands
corrode very easily when exposed to the salt spray, etc.  Everyone
should smear that cable with heavy grease periodically.  I posted to
the list about this a few years ago.
   I had that starter rebuilt, but it was a little more expensive than
usual because they had to replace the field coils: the end of that
pesky cable is welded to the field coil.

have fun,
Larry A.

On Tue, Jan 26, 2010 at 7:43 AM, Mark A Kippert <vanagon@kippert.com> wrote:
> I picked up my "new" '90 Carat this past Saturday and started going through it. When I tried to start it I get nothing from the starter (BTW I do hear the fuel pump charge).. After checking electrical connections and rapping on it with a hammer I crawled under the van to take a closer look and try to hook up a remote starter switch (to be honest I'm not sure which contacts to connect the two clips to).
>
> I �found that the electrical connections were clean and appeared to make good contact. However, while brushing dirt off the starter housing I found that the short ground wire from the motor housing to the solenoid was decaying badly. If I recall it's supposed to be a bare braided copper wire. This however was disintegrating and appeared red and flakey. I'm guessing this is my problem. I'm sure it will keep the motor from turning but would I still hear solenoid clicking? Is there a fix for this or will I need to replace the starter?
>
> Thanks!
> Mark K
> 1986 GL/2WD/4SPD
>