hi, all ive just bought some raceing rear sets for me nc30 2 use on the road,and they dont have anything on them for the brake light switch,so i bought a hydraulic switch but it keeps blowing the 15amp fuse in the box swapped wires around and still does it any1 have any ideas 2 why? thanks.

Do you mean when you wire in the hydraulic switch the fuse blows or only when you press on the brake lever.

it might be touching the frame..see if it has clearance

only does it when i touch front or rear brake.

Something not right then - why should the front brake affect the rear switch?

I reckon there is a short circuit in the system

CMSMJ1 wrote:Something not right then - why should the front brake affect the rear switch?

I reckon there is a short circuit in the system

Sometimes you can get a very weird fault... the brake light filament will fail, and the remains of it will burn themselves onto the taillight filament. When you add +12v through the brake light filament, so that creates a short.

Does it do this if you unplug the switch?

Are the two wires into the switch well insulated?

Is the hydralic switch a single wire car one, or a two wire one? If its a two wire switch, you deffo got a short somewere. time to dig out the multimeter.
Cheers
Ian

when its unpulgged its fine,so just 2 check i plugged the original 1 in and dont blow anything,its a 2 wire hydraulic switch.

Do you have a multimeter, if so check if either of the switch wires has continuity to the body of the switch.

cheers for ye help,im lucky i have another bike 2 ride as this is me project and 2 b honest its totally pissed me off the switch il sort but trying 2 get it 2 rev cleanly is the biggest problem ive checked mostly everything from wireing reg/rec carbs coils, speedo but she still wont rev cleanly i dont have the spare cash 2 get her in the garage,this must b doin everybodys heads in on here