Wiring help for trunk mount battery

7dart0 said

I tried 3 different voltage regulators all with the same outcome, way overcharging. I have almost 0 voltage drop from ground wire at the block to the Voltage regulator case. I have about a .2 volt drop from output sensor wire from the ignition bulkhead wire to positive side of the battery. I'm pretty sure the alternator let go. Its a reman unit from autozone about 2 years old. unless my one year old AGM battery is bad but it cranks over fine.

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Determine IF it is the alternator or the wiring. "The way it works" is that one field terminal is supplied 12V through (originally) the blue wire. This is same as "ignition run" switched by the key

The VR controls "the ground" on the remaining field terminal. That green wire might be grounded OR THE BRUSH in the alternator might be grounded. This seems especially to be a problem with rebuilts. Start by pulling the GREEN VR wire off and it should stop charging.

Also be SURE the VR is grounded and that there is no drop in the ground path from VR to battery.

And, be sure the VR connector is clean and tight.