Reply To: How to wire a vintage Airguide Tachometer for Magneto Motor?

[Gary H.]

Hi Steven- It looks like you can wire it to either M terminal on the ignition switch. They go to each ignition point set. Wiring a tachometer to old cars with points in the day, the trigger wire would attach to the negative side of the coil. The factory wire that attaches to the negative side of the coil goes to the ignition points. As far as which wire, black or yellow going to the M terminal, you may want to see if you can get a wiring diagram. I do not know if you reverse the polarity if it will hurt the tachometer.

Gary