1992 Mitsubishi Galant Where does this wire go?

I installed a new alternator on my girlfriend's 1992 Mitsubishi Galant. The wire "loom" or "harness" that goes to the alternator has the following wires:

1) main wire that goes to the stud coming out of the back of the alternator;

2) a plug with two terminals that plugs into the back of the alternator;

3) a single wire that goes into the oiil filter mount area;

4) a single wire, in a sleeve, with a single "barrel" type plug on trhe end that isn't connected to anything.


It's that fourth wire that isn't connected to anything that I'd like to know where to connect - it looks like a single, round, push on type plug.

Can anyone help? Reply to: robdob4@yahoo.com

Thanks

Rob