1979 Johnson V4 115 HP - Viking Deck

[pkimball]

I recently purchased an old Viking sport deck with a 115 hp outboard. Almost none of the instruments work and it run on an external fuel tank. Any idea on where to start? I want to reattach the tachometer. Do I wire the positive right into the ignition switch? I see the grey wire hanging out of the cable for the tach signal.

Thanks

 

[alldodge]

Welcome
Which 115hp motor do you have?

Most all electrical gauges work the same way. They require power coming from the key switch to turn them ON (Purple wire). Also require a ground (Black wire). There can also be a wire to light the gauge up at night.

Last is a sensor wire and will vary in color depending on which gauge it's for. In the case of the gray Tach wire it goes back to the motor