did you try the johnson red book at the url above the picture …. basic wiring layouts shown in theelectrical section … you can probably make your own harness if unable to find one
Well you might have to make a choice, look for a junction box and stuff to restore it back to original or hard-wire it. The original stuff is out there, but getting harder and harder to find. If you decide to go the hard-wire route, here is the wiring diagram
AN exact replacement aftermarket solenoid is a Sierra Marine 18-5807 that can be bought at NAPA auto stores as their number SME 185807. Or online at a lot of places like iboats.com. Just run a search for 18-5807.
Dave