Hi all,

I purchased some clocks for my BEC, and have everything working apart from the tachometer.

These are the instructions (that aren't very helpful). There is just one wire to the clocks for tach.
I've tried connecting it to a few different places on the coils but dont get any reading.



and my wiring diagram




Thanks!

I don't know, but on a car, the stock tacho usually is driven directly from the ECU or an aftermarket one is driven from the switched negative side of the coil - so either the black or green wires from the ignitor in your circuit and in that case there'd be two other wires ... a 12V supply and gnd for the gauge.

As that setup uses wasted spark, the tacho may read twice what it should, unless there is a way to set it to count half the pulse rate.

thanks. Yes, the tacho can be set to 2 or 4cyl. Setting to 2 should halve the RPM count