I have the same Prestolite in the upper left corner: http://www.ebasicpower.com/charge/alternatorwiring.htm
I was getting a light charge: 12.2 volts at idle, 12.7 volts at 2000 RPM, then dropped down to 12.2 again at full throttle.
In the process of troubleshooting, I noted the sense wire is...
