High Volts

Transplanted 440+6 into a 340 71 Challenger
Pegged Volt needle at mid RPMs
Shows 13Volts at Idle 18 volts at 2500RPM
? have swapped in 3 new voltage regs?
ballast resister HOT!
Ideas?

Yeah, there are two field wires to the alternator.

one of them, usually blue, goes tot eh feed side of the ballast and supplies a switched 12V to the alternator field.

The other, usually green, goes to the regulator and controls the return side of the field. This wire is shorted to ground, it should not be. Somewhere you pinched it in something, usually the valve cover.

Not really the "return side" but the negative field. We are talking about direct current.

ballast is normally hot when engine is running

but as mentioned is true the green field could be somehow being grounded to chassis somewhere, either the wire or the brush itself.

Unplug reg and check if green wire terminal is shorted to body/engine. If so, unplug also the green wire on back of alt. If still, the is the green wire, if not, is the alternator... brush, isolator, or some small internall short on alt producing a full field issue

I would be checking for a good ground on the voltage regulator and make sure that the battery voltage feedback is getting to the regulator.

got another used alt you can swap in? On the current alt ohm the (2) male field lugs on the alt & ohm each one to the nearby case. if an issue on either test you might pull the brush assys & see if anything is grounded that shouldn't be.

This is good advice. If you look at the wiring diagram you can see that the voltage regulator should be grounded and takes the reference voltage from the key side of the ballast resistor.

http://www.mopar1.us/charge.html

Agreed.

If blue wire is disconnected it will go full charge. Should have battery voltage on blue wire at regulator plug.