ive got an issue with my tach. after my truck warms up in the morning and i drive it a little it works fine and at idle it works fine. but then after a while of driving, when i slow to a stop (coasting) my tach goes to zero. and as im stopped i can tap the gas and the tach moves fine, but then moves back down to zero at idle. sorry for the crappy cell phone pic. hopefully it helps. and it is when im coasting to a stop. any idea why it does this? thanks in advance. 

ok will do. i asked marlin about it, and he said pretty much the same thing. that or my tach is toast..