I've searched for hours and can't find anything on the wiring of it. I'll be running a winch and LED light on roof. I'm thinking that along with running heater and headlights at night is gonna be more than the 40 amp stocker alternator can handle. I have the motor out now so I want to do this swap while it's easy to get to. I was going to get the trail gear bracket kit for the swap and one of the alternators they recommend on the site. There are alot of threads for the newer trucks with the internal regulator but mine has the external regulator mounted on the driver fender. I wouldn't mind going with the 1 wire due to simplicity, but my truck has a factory volt meter and I'd like it to work and really don't want to deal with the charge light being on all the time. If I can get the volt meter to work with the 1 wire GM I'd use it but from what I have found so far, sounds like the three wire will be needed for that. I have the 5 wire external voltage regulator on mine and the three wire plug on the back of my alternator with a green, yellow, and white with black stripe.I have found many folks asking for the same thing but mostly dead end threads. Has anyone did this swap and can help with what wire goes where? Here is pictures of my alternator plug and voltage regulator wires. I appreciate any help.

 

Anyone?

 

you might try this.

According to my 81 alternator plug wiring,
L= Yellow,
F= Green,
E= White/black.
It seems that the F & E wiring is pretty consistent in color code, with the L wiring changing through the years