Tilt/Trim Guage

Hi All:
Can anyone tell me how to hook up a Tilt/Trim guage on a 1999 Godfrey Party Craft Pontoon boat with a Yahama 2000 40 hp outboard. There are two wites connected to the guage, one brown and one purple and of course the black ground which is connected to gnd. The other two wires are about a foot long and have crimp conectors on them with screw lugs. This has been hooked up in the past and did work. Just can't remember where they connected.
Any help will be appreciated.
Where can I get a wiring diagram for the Yahama outboard?

Thanks

[boats.net]

It must not have Yamaha gauge or Yamaha wire harness(probably Godfrey installed gauge) My guess would be purple is key on power(probably ign terminal on gauge) and brown would connect to sender terminal on gauge.