crystal383

i just finished building a gen 1 small block chevy for my 87 camaro. i'm wiring the whole car myself. just enough for it to barely be streetable. (headlights, blinkers, brake lights, etc)

I have an old style three prong alternator. its got a two prong plug in on the side, and a post sticking out of the back. i just need to know which wire does what and where to run it to??

Apeiron

The stud is the charge output.

The terminal marked "1" is the field winding. Connect this to a switched +12V source through a charge warning lamp or a resistance wire. Do not connect it directly to a +12V without a resistance of some sort in series.

The terminal maked "2" is the voltage regulator sense wire, connect it directly to a +12V source, or to the output stud for convenience.

crystal383

I had tried to wire it myself once before. I ran a wire from the "1" terminal to a switched 12 volt source but it was just a regular wire. Then i ran a wire from terminal "2" to the positive battery post. And then I ran a wire from the charge output post to the positive battery post.
When i got to high rpm's sparks would come from the alternator.

So what I'm supposed to do is run terminal "1" to a switched 12 volt source using a charge warning lamp or resistance wire. And then terminal "2" to a 12 volt source using a normal wire.

What exactly is a charge warning lamp and resistance wire? And am I not supposed to run a wire from the charge post to anything?

jt1562000

You need to run a wire from your positive post on your battery to the post on the back of the alternator.
On the plug in connector on the side their should be two terminals marked 1 and 2.
You can run a wire from the stud on the back to terminal 2.
You need to run a 12v switched wire to terminal 1, either through a charge lamp, resistance wire, or diode. You can do a search to find out how to wire a diode if you no longer have a charge lamp connected. If you run a normal 12v switched wire to terminal 1 you will cause yourself many headaches. If you need me to go into more detail PM me.

crystal383

what exactly is a charge lamp or resistance wire or diode?

travis401

iTrader: (1)

Were would one aquire this resistance wire?

8t2 z-chev

terminal 1 goes to the diode trio for the internal voltage
regulator-it just needs to provide a little power to start
the alternator putting out voltage-if you do not have a
diode or charge lamp in place and have this wire
connected direct to ignition,when you try to shut the car
off the alternator will feed power OUT this wire and car
will not shut off A little 12v bulb such as #194 will
work fine for a charge lamp or a little 1 amp diode can
be used to stop the backfeed.

travis401

iTrader: (1)

Hmm, I always thought the car was just diesling, I guess it could have been the alt backfeeding the whole time. Good to know.

johndeere1986

Hey there i am trying to wire in my alternator on an 86 Chevy, it was a carborated 350 700 r 4 and i put a tbi 350 700r4 in it and i have the same 3 wire adapter, i bought a painless wiring harness in and have most all hooked up however im still trying to hook up the alternator and the ignition coil wires got any advice

crystal383

Man I wish I could help you but wiring is obviously not my thing.