The two wire plug that goes into the alternator in the back (was on the bottom of mine but not sure if that is standard or not). What is it for? I installed a new alternator that does not have a connection for this plug on it, but it seems to work fine. I thought maybe it was something for the voltage gauge, but the voltage gauge appears to be working fine as well.

Is this just something for the ECM? I've done away with my ECM anyway so if it is I wont worry about it hehe.

 

Contains a wire to the Ign switch that make the SI Alt charge
see
http://www.novaresource.org/alternator.htm

You obviously have installed a aftermarket " single wire" Alt that does not require this wire

 

Oh, hmm lol I always assumed my old alternator was what was referred to as a single wire alternator since it only had one terminal screw on the back of it that went to the battery lol. Figured a 2 line alternator would have had two lines going to the battery or something.

So just to confirm, this isn't going to hurt anything running this alternator is it? Like I said it seemed to be working fine for the few minutes I ran it. And I reved the engine up to around 4k rpm for about 20 seconds to make sure it did ok under high rpm and the voltage gauge never dropped below 13.

 

Single wire being just that ; only one wire, total

A SINGLE wire alt is one that is internally controlled and " self exciting" ;
meaning it doesn't need that other wire with the resistor on it to excite and start the Alt charging

 

Thank you for that info, but that still doesn't clarify for me whether this is going to cause a problem or should be ok to run?

I'm sorry, I'm really ignorant when it comes to these things, I'm learning as I can but right now I really just know how to take stuff apart and put it back together lol. I have no clue if a "self exciting" alternator is compatible without any other modifications with a system that apparently was not previously a self exciting system.

 

The other wire(s) are only needed for the stock non self exciting type Alt

If as you say your new one is charging correctly with only the power wire to the battery then you don't have a problem ;
just make safe the wires in the now redundant plug so they can not short out against anything

 

So I have a single wire plug alternator from a 96 chevy truck that I'm wanting to install on my car. Anyone done this. How would I hook this up!