tachometer

[dw711]

I have a tach that was in a previous boat hooked to a 1975 115 johnson is it useable with a 1982 90 horse merc 6 cyl. there are 4 wires coming from back of tach power(red) ground(black),grey and purple

 

[Dhadley]

Re: tachometer

The wires should be blue (light), black (ground), grey (tach lead) and purple (power from key switch).<br /><br />Good luck!