You can look it up in one of the shop manuals at MyMopar. I'm pretty sure that something like a 72 C body is external shunt. You can tell immediately by the size of the ammeter wires. Everybody who did this, GM, Ford, Mopar, used the harness as a shunt. The fords were particularly "numb." On my Rangers I've had you had to STARE at the ammeter while turning on the lights/ engine off, to see if it moved at all I actually thought about trying to implement this, until I found the "ammeter to voltmeter" old thread on here. If I were younger I might play with "this" some more
