I thought I understood how simple it was to hook up the tack from posts I have read but it doesn't work. I have the tach main leads (not the lights, they work) connected in series from the ignition switch to coil lead. Meaning the terminal that goes to the resistor wire has one tach lead, the other completes the circut connecting to the resitor wire! I have switched these both ways. I have not connected the ground wire up yet but did not think this would effect the tack, the clock yes. Could my tach just be bad or should I hook up the ground before I make stupid posts!!! Ha.