starting/electrical issues

[Ivan141]

About the tach signal converter: I assume the Omex item needs a 12v+ and gnd connection, same as the ones I built myself from time to time. If it drops you are probably experiencing voltage dips on the supply circuit when switching on other electronics.

The way those boosters work is they use 12v to charge a coil, and a transistor (driven by your low voltage tach signal) to break the coils ground circuit. That creates big voltage peaks at the output. If for some reason your coil does not get enough voltage to charge, the produced voltage spike may not be high enough to register on your cluster.

Another cause could be jitter on the tach signal, causing it to switch too fast..