I recently replaced my taillight on my klx250sf. At first, when I had everything wired up, the taillight nor the headlight would come on so I checked the fuse and sure enough I blew it. I replaced the fuse and everything was nice and lit up which I was very excited about. But then I applied the brakes and nothing happened. I traced all the wires to make sure everything was connected correctly and even adjusted the switch and no luck. If anyone could help me out it would be much appreciated.

 

Replaced the tail light bulb? the whole assembly with something different?

 

I had a fender eliminator kit on it, had been doing some wheelies and tore the taillight off so I replaced it with the same exact kit.

 

After replacing the fuse, and applying the brakes, did the fuse blow again?

If the fuse blew again, I'm guessing that there's a wire shorting out somewhere - once you press the brake, current goes down the wires and one of them (sounds like the brake light wire, rather than the running light wire) is bared and grounding somewhere.

 

Nah, the fuse is still in tact. I can press the brakes all I want and absolutely nothing happens. I wish the fuse would blow when I hit the brakes, atleast then I would have an idea of what would be wrong

 

Do you still have voltage going to the tail light when you hit the brakes? As others have said, most likely a shorted (grounded) wire, or you have it wired wrong.

 

If the fuse hasn't blow & the brake light is not coming on, and it used to. The wire for the brake circuit is not connected.
Alternately, you may not have a brake light bulb in the socket, or maybe that part of the bulb is defective.

 

I think you have the brake and tail light wires reversed.