OK so here's some fun I've had this spring... I have a '66 F100 with a 352 (?). I just acquired it last fall and it ran, but poorly. I updated the points to Pertronix and had the carb rebuilt which seemed to cure everything. I wound up pulling the motor this winter to chase some oil and exhaust leaks, and on the drive home from the muffler shop the engine quit. The ignition wire that goes from the starter solenoid to the firewall and down to the coil burnt up! I think it was a short between the ignition wire and the oil pressure sender wire, but I'm not positive. I started doing some troubleshooting to see what caused it, and wound up phoning Pertonix tech support. They sent me a checklist that led me to discover two things wrong - I had a 3.0 ohm coil instead of a 1.5 ohm coil, and I needed to eliminate the resistor wire from my ignition circuit. All of that was easy enough to do, and I had the truck running again in a day! However, now I'm really paying attention to my gauges, and I noticed that my amp gauge is pegged at 60 when I'm going down the road! I read a TON of posts here (CropDuster, you're a genius) and discovered that there's not a lot of information on wiring diagrams for trucks that have all 4 posts used on the voltage regulator. I was able to figure out there were 2 things contributing to my over-charging issue: 1 - the voltage regulator was shot; 2 - someone had moved the plugs in the wiring harness that connects to the regulator! In the end, I'm not 100% sure what caused the wires to melt down, but truck is running good! One thing still has me puzzled though - my ALT idiot light does not come on when I turn the key on. I think it should be lit when the key is on, but engine is not running. Can anyone confirm this?

I can't remember where I found this wiring diagram, but here it is again.

1966 F100 wiring diagram

 

Yes. The Alt light is on when the key is turned but the engine is not running.The same with the oil light.
I am running a solid state modern voltage regulator in my "65. They are cheap at the regular parts stores.

 

Thanks Kevin! I figured as much... I did buy a new solid state regulator which solved my charging issue, so now I just need to figure out why the idiot light isn't working. Amp meter works just fine though...

 

So, quick update. I found this link with a diagram for wiring the voltage regulator with an idiot light, and voila, it works! Apparently, the wiring diagram that I originally posted has the I and S connections to the regulator mixed up. Ironically, my regulator plug was wired correctly, and I swapped the wires around to match the wiring diagram... smh