I'm going down in flames, help.......the OTHER wire is the ground. You probably wont see it, it might be attached to the motor case/frame or more than likely it will exit the motor with the wire that goes to your switch or power.

These motors have to have a + and a -, just like the battery needs two cables to make a complete circuit.

This ground wire does not come out where it needs to be switched or fussed with, but it is there. GM didn't intend this motor to ground through some shiny place on its case..they painted the darn thing with nice black paint. That is why they put another wire to the motor...so it would make a complete circuit through the windings, so it would work!

Stuart