Re: 2000 yr. 225 hp. efi mercury outboard tach not working
In a normal mid range Merc wiring, grey is the pulsed signal to the tach, purple is switched 12v (from the ign switch) and black is gnd. For the tach to work, the input signal has to have pulses for the tach to count (with today's tachs) and they have to be the right configuration and the right number for the tach to display the correct rpm. A lot of gotchas there. For starters, the tach specs and alt specs need to be reviewed.
HTH,
Mark
