VDO tachometer and NS Regulator

[petedd]

I swapped out my engine and instruments with a Beta Marine engine with a VDO tach. I cannot get a good reading on my VDO tachometer. It either reads way high (off the scale) when the batteries are topped up or somewhat randomly (high or low) when the batteries are down a little, but mostly just reads off scale now. Is there a way to fix this or should I rig an inductive sensor (costs more than the tach itself) and stop trying to get a tach signal off the alternator? Thanks!

[Coulomb]

Answer is here: http://www.amplepower.com/primer/tach/index.html

[petedd]

Thank you. I will research a mechanical tach sender.