GM slow cranking starter remedy.
- Posted by DrChop on 1/15/2003, 11:29 pm, in reply to "Re: Battery
recomendations???" on the MTS messageboard.
The problem is that on GM cars there is a TON of wiring for the
current from the ign switch Start terminal to travel thru just to
get to the starter. Not only that, but the solenoid has to be pulled
in, and it's difficult and requires lots of amps to do this when the
windings in the solenoid are warm. As temp goes up so does
Do this. Take the wire coming from the harness to the S terminal on
the GM solenoid, and route it to a Ford solenoid mounted to the
firewall close to the starter. Inner fender panel will work just as
good. Take the large battery lead off the starter's large terminal
and mount to one of the large Ford solenoid studs. Run another
length of short welding or battery cable with a lug on each end to
connect the other large Ford solenoid terminal to the GM starter's
motor terminal. Here's the trick. If the lug that attaches to that
post is rotated, you will find a point where by drilling a small
hole through the cable lug, you will electrically link the large
post and the S post together with the lug. You want to do this, or
it will not kick out the starter's Bendix drive, as your original
wire is now on the remote solenoid. You have now electrically turned
your GM starter into a Ford type starter.
Ford solenoids typically take less amps to pull in and complete the
battery circuit to energise the starter motor. They are also cheaper
to replace. Here's the neat part. By drilling the cable lug to
connect the large post and the S post together, you are able to put
a ton of amps into the S post to energize the coil in the Gm
solenoid, which is now only used to engage/disengage the starter
drive. The unused Battery cable post on the GM solenoid is
FWIW, my old Jeep motor used the Ford style starters with a remote
solenoid and in the event of a solenoid failure, you could jump
across the large posts with a pair of pliers... try that with a GM
A lot of people claim to set this up and not have it work any
better. Most likely they are not wiring the short cable from the
Ford solenoid to the correct terminal on the GM starter. You want to
use the post that has the short, small bolt and spacer sleeve on it.
That is the motor winding that bolts on. If you use the original
large terminal, you're asking all that current to jump over 2 sets
of large contacts to crank the engine. Kinda dumb if you ask me.
Wire it up right and you can pretty much forget about needing to
change the starter, unless the motor does not turn (with a new
solenoid on it) or the Bendix does not kick out (motor turns fast,
no cranking from engine).
I'd rather change a fender mount solenoid any day than go underneath
and unbolt a heavy starter and risk it beaning me...