Alternator conversion question

[1974cj5]

Hey all you Jeep wiring gurus, I am trying to convert my charging system on my 1974 CJ5 to the GM SI series alternator.I have read the Junkyard Genius' excellent writeup on how to do this, but I have a couple of questions.

1) He says to connect the #2 wire for the alt to the "hot" side of the horn relay. I have searched all over and I am not finding a relay for the horn in my original wiring.

2)He says that the #1 wire runs through the idiot light to a keyed hot wire. Where in this setup would I wire in a ammeter or volt guage? :dunno:

 

[JR74CJ5]

Post the link to the "reading" you've been doing to help some of us understand the #whats etc you're talking about...



~ JR

 

[gert]

Yep I saw the write up as well.....the wiring is of no use to us though....look at painless wiring their manual for the the jeep wire harness has some pics in there that are of far more use to us..... the large terminal should go to the battery/solenoid pin 2 goes back to the big stud pin 1 goes to your fuse box hot....I believe the way it works is that this is your signal wire to the alternator on how much to charge/discharge on my 83 model it is pin 75A....take a look at your wire harness and find the hot wire from the fuse box that went to your regulator and that should go to pin 1 also the factory put a 15ohm resister inline on pin 1 this was to make sure the alternator will not keep your engine running after you shut off the ignition switch (it will run current backwards into the fuse box to keep the ignition powered) some vehicles need it some dont hope this helps http://www.painlesswiring.com/manuals.php

 

[Les]

The GM SI alternator is internally regulated and was easy to hookup back when I did it for a friend with his own Jeep. Here is a link to a forum that contains the basic diagram of how it is installed. The diode shown in the pic, between the coil and the alternator allows current to flow to the alternator to energize it during operation, but doesn't allow for current to flow back to the coil from the alternator....think "check valve", if you are not familiar with the concept. It replaces the need to wire to the idiot light in the dash if you don't want to or don't have one. When wired as illustrated, the alternator is energized from the supply side of the coil when you turn on your ignition key. Also, make sure you hook up the wire (#10 size) to the starter solenoid on the stud going to the battery, that is hot all the time, and not the other side, which is only powered during a starting operation...hope this helps.



GM Si Alternator Hookup

 

[1974cj5]

Thanks for all of the help guys, I think that I have it figured out now.