Hi.  I just purchased a yellow 2004 GS500F with 5000 miles on it.  The bike is in excellent condition and I really enjoy riding it.  However, I rode the bike for the first time at night, and I couldn't see a thing with the lightswitch at lowbeam.  I had to use the highbeam to get home!  So, I'm looking at the front headlight, and just the small bottom 'peanut' bulb is on.  This looks like a flashlight bulb to me. Is this normal for this bike?  Anyway, the main H4 bulb turns on when highbeam is selected.  Is the main H4 bulb supposed to be on at lowbeam?  Do I have a bad lowbeam H4 bulb?   

i believe it's a two stage kind of light.  Well my '90 GS is.

If the low beam isn't working but the high beam is its just a sign that the bulb is toast.  Happened to me last year.  Was riding some dark country roads at night when I had to switch to HIGH because the LOW just flickered out.  About 30 mins later the high went.... ugh.  good thing I was with a buddy.  Just followed his taillight's home.   

got a new light, works like a charm.