The lights on my 99 Sportsman 500 go from bright to dim all the time and I don't know why. All lighting connections are clean and die-electric greased.
Anybody know what needs to be replaced?

 

Sounds like your battery is getting weak or your stator/or rectifier is going out(which I doubt). My money would be on the battery. How old is it?

 

Battery is less than a year old and the light surging problem was there before the battery swap.

 

you need to check the voltage out as it might be your recifier going bad or having bad connections if you didn't clean that one.

 

I think it might be just the cooling fan kicking in doing it's cycle.
The fan comming on will make the headlights dim a bit on my Sp 450's also................
All depends on how much dimming your talking about.........Just a flicker or down right loss of light..........Caper...

 

My lights go from bright to dim while driving the bike, I might have bright lights for a few minutes then all of a sudden they go dim for awhile, this happens all the time while riding and it sucks.

 

did you check the voltage yet when they do thid to make sure it's still putting out correct amount?

 

Haven't checked voltage yet and all connections are good, I was told it could be a bad rectifier.

 

The Rectifier is my guess, I rode my ATV with a dead battery for a month before getting a new one and the lights still worked normal.

 

I just installed 3 HID lights on my bike and I'm going to findout if the surging continues with these new lights this morning (3:45 am) on my way to work.