2000 Trx350 es 4x4.

No power to starter switch. I can jump the relay and she fires up with ether. starter switch works then while running (tapped it). All fuses good. Brand new battery. Ground is good. I'm going to fig into the wiring from.the fuse box out. Ill.keep ya updated

 

Hold on, does the neutral light work? If it does, you are getting power from battery to ignition switch and beyond. If it doesn't, there can be a few problems, but you wrote the switch works when the engine is running, so main 30 amp fuse is most likely, and blowing it due to whoever fitted the battery, connecting it up the wrong way round, is a likely cause. Check, with a test lamp, if you get power from battery to voltage reg. (the green and the red wires).

 

The lights all work when running. That's it. All fuses are new. No wires loose. No corrosion. I have a feeling I need a new fuse block

 

My question was does the neutral light (and for that matter the headlights etc,) work with ignition on but it not started? If it doesn't, then the fault is between battery and 30 amp fuse or 30 amp fuse and regulator. I have had this a couple of times and it has been an almost invisible crack in the wire's insulation, this lets water in, the wire turns to verdigris for about 1/4" and doesn't let full power through, which is why I suggest an incandescent test lamp, as this requires power to light it, rather than just volts, which you may still get via a voltmeter.

Incidentally, "the boss" has just treated me to a new test lamp, turns out to have LEDs inside it which renders it useless for power testing, also won't work if polarity isn't right for it, why make something more complex and which destroys it's function?