Magnum swap using Magnum alternator

Evan Dutch said
Hey guys,

Working on finishing up my magnum swap in my 1971 Scamp and I’ve got something I need help with. I am running the magnum serpentine belt setup so I will be using an alternator that came factory on this magnum engine. My battery will be in the trunk instead of under the hood.

My question; this alternator is rated for 90amps. My ammeter will be bypassed, this is not a one wire alternator so I plan on using the two field wires like the original alternator did. Is this amperage rating too much for the car even if the ammeter is bypassed?

Also, would anyone be able to tell me where the black wire that attaches to the back of the alternator goes once it passes through the ammeter? I know it needs to be returned to the battery to compete the charging circuit.

I also plan to use a circuit like the one @crackedback has designed. But I am unsure how to get it to work with my application since it is drawn using a 1 wire alternator.

Any help would be greatly appreciated!

Thanks

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The wiring you showed will work fine as long as you bypass the ammeter. The large charge cable from your altern Will be the one in that diagram.

You need to get an electronic voltage regulator like used on most 70s Mopar cars and trucks. One small field wire of your alternator goes to the regulator. The other small field wire goes to a fused ignition source.

This electronic regulator must be case grounded to the body. Most currently available regulators are hit-and-miss for quality. Mine was overcharging. I think someone was selling used and new old stock good quality regulators and maybe he still has some. Maybe it was @halifaxhops