on my last run cross country, the on my 14 lights started going and coming, & the turn signals would not work properly By the time I got it home the bike was akin to an ambulance with flashing intermittent lights. Thankfully the motor ran fine.
I ran a check on everything I could think of ..and finally with my brothers help we finally found the problem. The junction of several grounds with one ground leading out on the riders left side - a supposedly waterproof connection point ..was completely hooped. The thing had over heated and apparently caught on fire by the look of it. Into that mess of bare wires water had entered and helpfully corroded the snot out of works.
We stripped that whole thing apart and provided a more substantial ground wire going out, grounded in a different spot.
Why did it happen? The only answer seems to be the accessories we added. The Heated grips,etc. over taxed/heated that weensy only just capable outgoing ground wire.
Now fixed the bike runs as per usual- like a land rocket. The 40K on the motor has not diminished the acceleration or fun this bike gives.

My two heated gear harnesses are connected directly to the battery with inline fuses. The power lead for the rqadar detector is connected to the hot lead (with an inline fuse) and grounded to the frame. No issues so far, but I think a fuse would blow if anything went awry.