Charging woes

Merry Christmas everyone,

I’m having some issues with the charging system on my 1971 Plymouth scamp. The car has a 360 magnum and I’m using a Holley terminator computer to control the fuel injection. I’m using a magnum front drive and the alternator from a 360 magnum.

When running, the car appears to be overcharging the battery. I’ve seen anywhere from 16-18 volts. This battery is located in the trunk and is brand new and fully charged and has been verified to be a good battery. It is an AGM battery (unsure if that makes a difference)

I’ve got the blue and green field wires from the factory harness attached to the rear of the alternator and the charging wire running from the alternator to the trunk mounted battery. I’ve replaced the voltage regulator, checked continuity between the regulator and the alternator lead wires and I have tested to check and see if 12volts is present at the blue field wire when the key is in the run position. I’ve also checked voltage drops across the field wires and ensured the regulator is well grounded. Everything has come back good so far. Ammeter bypass has been performed as well.

I’m stuck as to why it’s still overcharging. Any ideas?

Thanks guys