97 175 Intruder. I replaced the tach because the old one has not worked since I had the boat. Before I replaved teh tach, the old one had started to fluctuate, previously it had just been pegged out. I have a service manual for the motor on the way, but was hoping somebody could steer me in the right direction. The new tach stays at zero, and none of the lights are changing when I turn the motor over. Help please.