[Tom Wesenberg]

The red wire goes to the switch and then to the points, so this is the ground wire and you should show 0 volts with the key on and points closed, as Mitch said.

Since you show 2 volts, that tells me the points contacts must need to be cleaned. A couple strokes with a points file or fine sandpaper should work.

If you have an original popout switch with the original wire, it could also be the original wire is partially shorting to ground, and thus the 2 volt reading. Hold the points open and see if you still show 2 volts. If you do, then the wire or switch is at fault.