Alternator wiring ?'s

[sick620]

1979 620. Its internally regulated. There were 4 wires total, two going to the back, and two going to a plug in clip. Well I just installed a gm one wire, wich wires need to be ran to it? Does the alternator need something to tell it to turn on? HELP MEH!!??

[sick620]

http://olddatsuns.com/data/dat620-1979.pdf

found this but cant make sense of it!

[datsunaholic]

If it's a true GM 1-wire, then all you hook up is the big fat white one with the red stripe, that came off the BAT terminal. The GM 1-wire is self-exciting. For best performance you should really add a ground wire though, as the pivot points aren't good grounds. The original ground was the black wire with a ring terminal.

 

However, at this point your alternator light won't work nor will your automatic choke relay (if you still use the electric choke) as those are powered by the wires in the little plug. A true 1-wire has no place for those to go. Some "so called" 1-wire alts do have an output for a charge light, and normal internally-regulated GM alternators MUST use the ALT light because the GEN light circuit is what excites the alternator.

[sick620]

http://community.ratsun.net/topic/21387-how-to-install-gm-105-amp-alternator/page__pid__396515__st__20#entry396515

 

its this alternator...

[sick620]

whats needed for that alt datsunholic?

[datsunaholic]

I have no idea. There are a million GM alternator diagrams out there and every one shows a different way to wire them. Most are for the GM "3 wire" alternator. One wire (the BAT wire) is the same as on the original Hitachi- that's the main output wire. The other 2 are in the plug. One almost always simply goes back to the battery, which is also exactly how the Datsun did it in '78-79. So, one wire is "hot" in the T-plug ALL THE TIME. That's wire #2 on the Delco alternator, and it's the yellow wire in the T-plug in the Datsun. #1 wire in the Delco alternator goes to the CHARGE warning light. The problem is, in a Datsun (that's the White wire/red stripe in the T-plug) the Charge light gets 12V from the alternator and is grounded at the dash. In the Delco, the idiot light gets 12V at the dash and grounds at the alternator. At least, that's how most diagrams show it.