Hey Mike,

Maybe this could you, I used to get electricals problem too with water projections or rain.
That the conclusion I found after 5 years under the rain

I identified 4 main problems with the electrics with the XT, the fuse connection, spark plug and the ignition coil, AND THE STARTER RELAY.

As the mud guard is very short all the water goes directlty onto the sparkplug and ignition coil if the wire linking the ignition coil and the sparkclub cap is not tight the slight amount of water causes problem, I would first check that.

I myself covered the all area spark plug to ignition coil with a old bycicle tube, everyting is then dry at all time.

I added an extension to the mudguard to reduce the water projections, you could also get those after market mudguard used on moutain bike and to be fixed on the frame.

Same story for the main fuse should some water get into the fuse box , you will have faulty connection, I too covered this area with an old bicycle tube .

Now the starter relay can get rusty two, when its gets tooo bad even if the outside looks ok you won't be able to start your bike.Now the trick would be to short cut directly the starter with the + of the Battery with a cable if you find yourself unable to oush start the bike with a heavy loads or just because the road is muddy.
As per before . cover the starter relay with some kind of old bycicle tube...

I'm pretty sure that if you do all of that you won't encounter any problem with water or at least have an idea on how to fix them...

Cheers

Gwel