TAMD alternator sensor wire

I recently replaced my Magnasine inverter, Magnum ME-BMK monitor and isolators with a Victron inverter, Cerbo-GX and DC-DC chargers. At the end of this project I ended up with a wire from the alternator that I don't know where it goes, and I can't find it in any of my photos or the wiring sketches I made before ripping everything out. It is a small gauge yellow wire and connects to the terminal at the bottom of the alternator which I believe is the D+ terminal. When I start up I now get the low voltage alarm on the TAMD alarm panel. This wire must have previously connected to the ME-BMK monitor as I don't recall removing any small gauge wires from anywhere else. I can't figure out how this would have provided a voltage signal to the TAMD alarm panel. I saw from a post last year on similar alternators that there are some very knowledgeable folks here that I'm hoping can help me figure out how this should be connected.

This is the best pic I have of it. Just to clarify, the yellow wire is still connected to the alternator, it's just no longer connected to anything on the other end, and I was a dummy and didn't record where it went before I removed all the battery monitoring wires.

Thanks! Underway now on the way to haul out for a paint job but will try that when I can get an opportunity
Magnum was fine just 14 years old and I’m doing some upgrading so ….

Will do.
Connected the wire to the positive terminal on the start battery while underway and after a couple of minutes it started generating, so thanks for the advice on this.