I am a dummy, the wire is leading to the condenser. Removes voltage spikes and quiets radio noise...... I cant recall, but I think it goes to the 5v output leg. Also. there was a paper insulator in there.... if you didnt pull the gauge cluster, it could be tough to line everything back up.
I have about 3 of the old style VR I can bench test them later and post my readings if you like
