I was wondering if someone could give me a had with my tach gauge..I have tried about 6 Different gauges with the same result. I just can get the stupid thing to work...I have to be missing something...When I turn the key the gauge jumps up a little...When I start the motor nothing.. Because I see the gauge move, that tells me I am receiving a signal from somewhere, but the dog on thing just won't work..I even pulled a gauge from a friends boat that we knew worked nothing,,,I played with the pole switch on the back nothing, I traced the purple wire back to the motor it its connected. I believe I have a ground, because the gauge light works...I know i'm receiving some sort of signal because the gauge does more with the switch.....What am I missing...