help wiring a trim gauge

[dogdoc2006]

I bought a used boat with a '03 evinrude 115 ficht (E115fplslb). The boat doesn't have a trim gauge and I am trying to put one in. <br /><br />I found the trim sender unit next to the trim motor. It looks like the wires from the sender unit go into the engine case, where i can't make them out. They are covered in a black overwrap and I can't make out their color pattern.<br /><br />I assume the wires extend up to the dashboard with the other wires. I pulled the dashboard off and found the wiring harness entering the dashboard. There are a few wires not being used.<br /><br />My questions are: What color are the wires for the trim sending unit? Are those wires likely to be behind the dash with the rest of the engine wiring even though the boat hasn't had a trim gauge before?<br /><br />thanks