Posted by CGarbee on Tuesday, March 01, 2005 at 10:38AM :
In Reply to: Alternator Wiring Help?? posted by Dan Shockley on Monday, February 28, 2005 at 10:25PM :
A good page with info on the Delco 10SI and other Delco(GM) alternators of similar construction is located at:
http://www.oldengine.org/unfaq/10si.htm
I also have a page that talks about this alternator and other issues related to playing with a 12volt conversion in a M37 as part of a diesel swap located at:
http://www.garbee.net/~cabell/12voltconversion.htm
In my truck with a Delco 10SI hooked up to the Cummins 4BT:
The Cummins came with a Delco 10SI already attached to it, so all I had to do was figure out how and where to connect the three wires coming off the alternator, and what parts of the original setup to remove. I disconnected the wiring harness plug from the original voltage regulator and removed the regulator from the truck leaving the bracket in place. I then cut wire #10 a few inches back from the plug leaving enough wire that I could splice a line onto the plug for possible future use. I then took a 8 guage wire and ran it from the battery box to wire #10 in order to provide power to the existing electrical systems in the truck. I then connected the large lead from the alternator to the starter post where the positive lead from the battery and slave connector are connected to the starter using a 8 guage wire. I ran a 12 guage wire from pin 2 (marked "F") of the alternator to the original ignition switch in the truck in order to provide the voltage signal to the alternator's internal voltage regulator. I then ran a 12 guage lead from pin 1 (marked "R") of the alternator to the tachometer as described on the Datcon Guages page.
Good luck.