Tach help please

[shavedhead]

1999 merc. 50 Boat had no tach,I installed a seascape eclipse tach, along with Tach harness to plug into controls,ran purple wire to + gray wire to sig. ran a ground from my ground bus to the- , the blk wire from harness not connected somewhere Checked it with meter and went to ground and nothing on continuity setting. Thats why I ran from bus to ground on meter. Tach set on 6p,went to lake today and nothing, any ideas? Thanks for your help.

 

[danvhp]

From what I understand about the tach connection on the voltage regulator, the gray lead has a variable voltage on it depending on RPM. Connect your DVM to the purple wire you ran to the voltage regulator and ground and see if you a DC voltage that varies with engine RPM. Even if the voltage regulator is charging the battery, the regulator can be bad in regards to the tach output.