Good luck, i used to have a 1997 yamaha tenere and 3 months old I took it back for warranty "intermittent start".
I had taken a rock onto the loom under the rear mudguard, and every time it got wet, no electrics.
Your fault could be in a number of places..
You might find it by turning the key to aux, and operating the indicators, and then hose the bike a small part at a time.
You could have a leaking indicator lens, do your lenses fill with water after washing?
Do you have a hazard switch?
John