I found a 80 something 210 in the wreckers and noticed its alternator was 50 amps instead of my 45 amp one so I pulled it for 35 bucks.

Afetr installing it on my B210 I noticed it says on it IC REG built in.

The B210 has an external regulator. Now the CHG light stays on and I cant turn the car off with the key, I have to yank the coil lead.

Can I make this alternator work or do I have to go back?

you need to re-wire it, removing the external regulator

i did it myself staring at the wirring diagram for a while i figured it out for the 1200

but you could get an auto elec to do it for about $55

edit: (sorry thats aus dollars, um, about one hours labour whatever thats worth over there)

does that sound normal that it would keep running after turning the key off?

im not sure what you've done exactly

but turning the key off normally cuts power to the coil which cuts spark from the motor

now after doing what you've done i have no idea what implication that would have but i pressure you are putting charge through wires that your not supposed to

yes,thats completely normal.the ignition circuit is still getting power through the 2 regulators.
you can fix the problem by disconnecting the external regulator,then running a wire between 2 of the wires.i can't remember what two they
are,but i seem to remember they are small diameter yellow.i've done the conversion three or four times,always no problems.

Easy wiring fix: Datsun 1200 WiringQuote:

OK, I bridged the White Blue and the White Black wires and put the alternator back in.

The CHG light now stays off. Good.
The car still wont kill when the key is turned. Bad.

hmmm.

So, after running the car after a day the difference in apparent voltage is amazing. The lights are brighter the wipers run faster the radio doesnt cut out, the cigarette lighter pops out 5 times faster, the heater dries my eyes out in minutes.

On the down side, the car is running a bit rougher in the low end and obviously the not being able to turn off the car without popping the hood is a real pain in the boot.

If anyone has done this conversion and knows what I, and the tech section here doesnt, please let us know.

I recommend this conversion highly as I have gone through 3 regulators none of which have supplied the correct voltage. 2 of which over charged at over 15.7 volts.

At the six plug connector, find the wire that goes to the s terminal on the alternator, bridge it to either the ignition feed, battery +, or you can leave it off, after trying all three options you will find about 0.2 of a volt difference. you don't want your voltage anything over 14.7 volts at any time.

Yes, agreed.

Keith, I did the conversion recently, took the photos and created the Tech Section article. Make sure you unplug the external regulator, and leave it unplugged. If you've already done that, let me know, and I'll review the article and my 1200 and make any needed corrections.