65amp wiring/trouble shooting
Overvoltage is almost always easy
1...Can be shorted brush holder in the alternator causing it to "full field." This will have to be on the green wire connection, OR a short in the green to ground, which has happened
2...Poorly grounded VR or ungrounded VR,
3...Bad VR
4...Drop in the ignition circuit, which powers the VR and thus causes it to "think" the battery is low, and ramp up charge
HOW TO FIND
A...Turn key to 'run', engine stopped. Hook one lead of multimeter to "run" buss as close as you can get to VR WITHOUT disconnecting anything. The ballast or the blue alternator field wire. Stab remaining meter lead into the battery POS post. You should read very little, the less the better. Over .3V (3/10 of 1 volt) you need to investigate drop in the "run" circuit
Above is where adding an ignition relay comes in, as I've mentioned before
B....Can be in VR ground circuit. Run engine to warm, normalize battery. With engine running on fast idle to simulate low to medium cruise RPM, stab one probe of meter into battery NEG post, and stab other into VR mounting flange. Be sure to get through chrome, paint, rust. As above, you hope to read very little, zero is perfect.
A good way to improve battery-to-body ground is to run a jumper from an unused hole on the rear of the driver side head to the firewall, such as the master cylinder mount studs. But a "Ford style" starter cable, AKA eyelet to eyelet about a foot, foot and a half long
5...Shorted brush. The green VR wire controls "the amount of ground" so to say on the field, which is supplied switched 12V on the blue wire. Pull the field wires, check each to the case for continuity. They should be open/ infinity.
6...If none of this fixes the problem, replace the VR. WHILE DOING SO, check the VR connector for good connection. I got "waylayed" as I was going to try this but I THINK a .177 caliber rifle cleaning brush will enter those connector terminals.