03 Johnson 90 no power to starter motor coil

Hello I have a J90PL4SR 03 model that won`t start.Battery is fully charged. I`ve checked the controller ok and there is 12v getting back to the outboard when the start key is turned. The 12v gets as far as a little black box about the size of a matchbox. Start Solenoid clicks in when I short it to the + terminal of the starter motor. I haven`t run the boat for 5 months any help is appreciated.
thanks Paul.Note the insulation scratched off brown wire this is where I tested for 12v with key turned.

kill switch lanyard in place?there is also a inline fuse in the wiring harness under the cowl...

According to a Evinrude / Suzuki repair manual.----------Check nuetral switch on engine.----Check nuetral switch in control box.---Check 30 amp fuse on engine.

I traced the wire back from the starter coil to the start relay it was ok. Then traced the wire from the start relay to the neutral switch! It was broken. I`ve bridged it out until I get a replacement thanks for your help.