My bike (2001 CBR 600 f4i) will be running in neutral or riding. Suddenly the headlight will dim to nearly off. At the same time the icons for turns,highbeams,FI come on. Maybe 10 seconds then back to normal. The bike did shut off once with this problem while riding. Pulled over restarted and went home. I took the headlight assembly off and disconnected all connectors checked for corrosion. Sprayed with plastic friendly contact cleaner. Checked battery terminals. Removed computer. No corrosion. Put bike together and have not seen the problem occur. I have only put maybe 10 miles on bike since. Maybe its gone maybe not. Point is have anyone had this issue,found cause. Any advise would be appreciated.

 

Not saying that's the prob in your case but when starter switches start getting old/worn, you can see them affecting the headlight. Its def like there's a gremlin in the electrical system...can get a dif effect from one instance to the next.

I've seen where a starter switch will stick (not rebound completely back out) after a start. The bike will run but...no headlight, headlight will flicker after start but go out, or some variation of that. Sometimes, you can just put a little wd40 on that puppy & be good to go. Other times, you have to replace it.

Anyway, hope your prob is solved.