The number 4 wire from the regulator to the starter what is it's purpose

[Matthew Welcher PWA]

On the standard M37 2 wire regulator harness, the #4 wire that goes from the out put side of the regulator to the starter switch. Then the #10 wire from that harness goes to the circuit breakers. Which then powers everything internally under the dash so to speak.

How what and where does the voltage inside of that regulator function?

And or the path of voltage, how does it travel and what directions?

I have wired dozens of these trucks, I do not have a complete under standing Is it that the voltage from the regulator charges the batteries through the #4 wire to the starter?

Thanks for thinking about this with me.

[Tom Petroff]

Your on the right track.
# 4 wire charges the battery when running and discharges when not running.
#10 Wire supplies power to the truck via the #4 through the regulator.

The Amp meter on early models is wired parallel to the regulator via #8 & 9 wire.
The Volt meter on later models is tapped off of the #10 wire through Ign.
Switch.

Not sure if I helped but I tried.
Tom

[DODGEBOYS]

[Matthew Welcher PWA]

Thank you, i have this diagram blown up into poster board size in the shop.

I was trying to track the path of voltage, as when and where and to and from. I actually enjoy wiring the M37's quite a bit.