I have done a quick search and couldn't find any answers to quite the same problem.
I have a 2010 M1100S. I recently did a DIY conversion from the stock indicators to Rizoma Avio21 LED indicators. I read the instructions and added a single resistor to each indicator, but am not an expert electrician so my wiring may leave a little to be desired. This may or may not be relevant to the problem I am having.
My headlights work fine. My parking lights work fine. The brake light and license plate light work fine. After a few hiccups my indicators work fine. With the main switch even the high beam headlights work fine, it is just the passing light (ie the high beams using the switch on the front of the switch gear) which is temperamental. Sometimes it works and others it doesn't.
I'm guessing there is a loose connection, probably behind the headlight assembly as I took that down to change the indicators and haven't touched the switch gear. Tomorrow I'm planning on pulling the headlight off again and having a look but thought I'd post and see if the "collective wisdom" would give me any pointers for which wires might be the potential culprits.
I ride my bike every ay and it is a tad over 1 year old so I don't think it is a battery issue.
Any help would be appreciated.