i a 1981 evirinrude 115hp with the power pilot control. under the ignition key and the throttle tension adjuster there is a 3 pronged harness connector. the 3 wires at the connection on the controller are black,purple and gray. i believe this is for the tach,right? anyway heres what i found, the black is ground as i figured, with the key on enginre not running i have 12v on the purple wire and 0.45 on the gray wire. at the other end of the harness the purple wire has tuned into 2 purple wires, one which is hooked up to the tilt/trim gauge which hasn't worked since i got the boat . the black wire also has turned into 2 black wires, one is tied into a group of wires to the gauges for the ground. i have the 3 wires, black,purple and gray that are unhooked that i assume go the tach. nothing is hooked to the tach and this is the way i got the boat. the tach connections are marked so the black will go to the ground connector, what do the purple and gray ones go to? thanks in advance.