[Xavier]

My Tach does nothing. I have a msd 6al ignition box that supplies tach feed to a tach that was just checked by the mfg to be fine, no problems supposedly. The msd 6al is running the car fine, but after checking everything and a very simple tach hook up, tach does not work. If I am running a msd ignition box, can I still use the negative side of the coil to give tach feedback? Just rather get the tach feed somewhere else than to replace the ignition box.

Thanks.