Engine dies while driving - tach drops to zero (MSD)

[AdamIsAdam]

Originally Posted by patrickt

Just pull the fuse that feeds the dash gauges and take her for a spin. IIRC, that tach wire is just a 12v square wave.

Doh! I hate when I don't think of the obvious. That fuse controls all gauges, but also apparently the radiator fan, but I should be ok for a while anyway without over heating, not that I'll know without a temp gauge lol. I'll go tomorrow in the daylight. tnx

Originally Posted by jhv48

Ignition switch is my bet. Start simple then go complex.

Yea, I ordered one (a different brand) already that someone (a professional builder) on the FFR forums said is more reliable. But with only 1,600 miles and it feeling so good/solid, I wonder how likely that is.

I verified that the ground being used has the same volts as when I put my meter to the battery directly. I'll relocate it anyway, but I don't think that's the problem.

My money is on either the ignition switch or the tach. I feel that if it's worked fine for the first 300 miles and a few months I've owned it, and assume it worked for the prior owner, then why would wiring suddenly go bad?

I don't think it's the MSD box itself and I am pretty confident it's not the coil, although I have a spare new one I can swap in if need be.