Last Fall I put a brand new battery in my '88 KLR 650. It has always run fine. Just turned 32K miles on it.
Yesterday evening I went for a 60 mile sunset ride and noticed on the return trip that my gauge lights seemed kind of dim and as it turned dark my headlight was very dim. Eventually when I got to a traffic light my turn signal stopped blinking and then just stayed yellow. So I just kept riding as dusk became dark and did my best. The engine ran fine no matter what. . .just the lights going south. At one point they flickered bright (normal) for a split second but never again.
To make a long story short I did get home. Oncoming cars were leaving their high beams on because I don't think they were sure what I was. My headlight was on . . . but barely. Fortunately I got to a point in the ride where there were a lot of overhead street lights.
This morning I started up the bike. No problems. The lights seemed OK. The turn signals worked. . .although the right one seemed to blink a bit faster than the left one. It was hard to tell but I think as I revved up the engine the headlight dimmed a bit just looking at it. I didn't take it for a ride today. Am trying to think this one out. I'm doubting "B" voltage or a short. Maybe a loose ground somewhere?
The headlight seems to pulse a bit at idle. There was a section of road I traveled the night before that had some really bad frost heaves and it was quite bumpy so I'm wondering if something got knocked around. Since the machine is going on 31 years old it could possibly be a charging system component, relay, rectifier, etc. . ..
Anyhow, I'll just have to start at the battery and work my way forward along the wire trail to make sure everything is tight and connected and no metal to metal spots where a wire may have rubbed on the frame for too long. If it all seems OK there then I go to the tail light and rear signals. If that seems OK then I'm thinking it's charging system components.
This all came on rather suddenly. The bike looks like it's only a couple of years old. It's always garaged. No mice in it. At the end of the day I'll just roll up my sleeves and deal with it. . ..

This pic was taken of it back in 2012.