1964 battery drain

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Last seen
Mar 14, 2023
Thunderbird Year
have a mystery battery drain that drains battery overnight. happened after engine reinstall. thought it was the alternator because if i disconnected wiring from alternator drain would stop. purchased new alternator and still get same issue. suggestions appreciated.
Could be a voltage regulator issue. Or an open trunk or a bunch of things
1964 was the first year for the alternator in the Thunderbird. The voltage regulator was not built into the alternator but instead is mounted near the radiator IIRC (if I remember correctly). Unplug it and see if the drain stops.
I would suggest a battery cut off that mounts on the negative battery post.

I would certainly unhook the battery at night. That would prevent a possible fire and verify a short.
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I would start pulling fuses, one by one, and check for current flow out of battery
can anyone tell me the proper wiring of the alternator and voltage regulator? what voltage (if any) should be on each color wire? thanks