Re: 1998 Force 75HP unconnected brown wires
From the wiring diagram in my Clymer manual, it looks like the Brown/White wire is for an optional trim indicator. The Tan lead goes to the accessories connector under the dash. It depends on what year and the type of set up you have as far as what it's actually used for in your particular case. Either way, it looks like they are probably for optional accessories. That's my guess.