If it does start then it is likely you have a corroded connector where the harness joins one section to another, you just have to open them one at a time and observe any bent prongs, if you see green foamy stuff this should be cleaned by soaking in a small bowl with baking soda water to dissolve the foam so you can observe the actual connector parts, electrical problems are solved by locating them, you just move along until you find it, and fix it.
If the plug wires do not stay tight inside the plug connector you can clip 1/4 inch wire off and screw them back on to get a better bite of the wire core so they can not vibrate loose while riding.
