tachometer connection 3 wire 1985 90 hp evinrude

[simplydave]

from the control box there is a three wire mini harness running to the back of my presently non working tachometer. Present wire connections are: grey to the light post, red to the ignition post, white to the ground.

I know this can't be correct and think it should be: Grey to sender post/red to ignition/ white ? with a separate lead run for ground and lite from a buss bar and switch.

looking at the three wire control box plug interior it's grey/left bottom/ red/right bottom/ white center top.

any help is greatly appreciated.

 

[Silvertip]

Gray - send terminal on tachometer.
red = 12 volts from any other gauge or the "I" (run) position on ignition switch.
White = ground from any other gauge or the ground bus wherever you find it.
The internal light connects to the light terminal on any other gauge or the NAV side of the NAV/ANC switch.

 

[simplydave]

thanks, that's my tomorrow project. thanks again.

 

[64osby]

You may find your current tach is still good.

 

[simplydave]

yeah, I'm thinking in the same direction. I've re-done and done things that haven't been done to this motor in a long time. When I pulled the plugs they were gapped at .45, 30, 40, 45. the coils were melted a bit and I was missing linkage plastics. Sea trials are a week away.