Hooking up a 70's tach

[kciv]

I have an old 70's Johnson Tach that I want to hook up to my 1979 70HP Johnson outboard. The three wires coming off the control box are black, gray, and purple. How do I hook this tach up? The tach part number is OMC291274. What does the plug that goes in the socket look like. Does anyone have pictures? Web site?

 

[Barnacle_Bill]

Re: Hooking up a 70's tach

Its just a simple harness that plugs into that plug. Brown goes to the send post, black to the - post, and purple to the + post.

 

[kciv]

Re: Hooking up a 70's tach

bhile

I think the wires are

Black = Ground
Gray = Sensor
Purple = 12v power

On the tach I have two shovel connectors and the socket. No marking on all three.