I have a SW tach that I just installed, as the diagram below. Problem is that when I turn the ign. to the on position , the tach needle goes to 4000 without the motor running. I got the tach wire on the neg. side of the coil, when I take it off, the tach reads 0. I'm running a Pertronix Flame Thrower coil and a Pertronix Ignitor electronic ignition in my distributor, do I have to wire it different than the dia.???


Tom.