[SlowPoke]

Please let me know how you make out. I recently took possession of a 1988 3100 and am the same boat.

Two different attempts to get the information from Tiara resulted in an owners manual for a 1998 model and being told, by two different customer reps, that they didn't have wiring documentation that went back that far.

I've been de-constructing all of the wiring---wire by wire---and am down to a solitary black 12v wire, labeled as #6 (in a factory bundle) that the breaker says Battery Charger. The boat no longer has the factory charger. I had hoped it was simply repurposed for the replacement inverter/charger but no such luck.

Any idea where the factory charger was initially installed in you 90' ?

There is a tool I've used by Triplett called Fox and Hound. With a pair of clip leads, you clip on to the wire you're trying to trace and then using a probe, you just follow the beeps and flashing lights and trace down the wire with the signal on it. If I had known I was going to spend this much time on the job, I would have bought one in the first place. Maybe there's an app for that