Fried ECM
Schematically it should be like this. If not, mark it up.
The solid black dot is a welded splice wrapped in electric tape. Leave it alone.
Adding a third wire to that terminal connection should work. Honestly its not a great way to do it.
I'd either piggy back it there with one of these
Splice it in permanent or attach it at the regulator.
I think there is one year where some ignition wires goes to regulator first. Only you can say what you have there.
Schematically it should be like this. If not, mark it up.
The solid black dot is a welded splice wrapped in electric tape. Leave it alone.
Adding a third wire to that terminal connection should work. Honestly its not a great way to do it.
I'd either piggy back it there with one of these
Splice it in permanent or attach it at the regulator.
I think there is one year where some ignition wires goes to regulator first. Only you can say what you have there.