Customising bike, issue with new tail light...

[awf1974]

Hi there guys,

I am customising and modifying my GZ and have recently purchased a Sparto tail light copy but am having some trouble installing it.

The light came with two wires, red and black, I thought no worries so I dismantled and clipped off the old tail light and housing to find three wires, one brown two black and white.

On the original light the brown and one of the black and white are attached to the rear of the bulb/globe, the other black and white is earthed into the housing.

So I strip the wires back and temporarily attach them to find out what does what, I can get the 'minor' (tail light) filament to come on without a worry just by attaching brown to red and solid black to one of the black and whites, but I can't get the 'major' (brake light) filament to come on no matter what I seem to do - I am operating the front lever and/or footbrake by the way...

I am able to make the brake light filament come on permanently (without operating brakes) if I attach red to brown, solid black to black and white and the other black and white is earthed to the housing.

So I go back to the original light to see if I can figure out how that one worked, brown to brown, black and whites together and the tail light comes on but not the brake light...

So my question is, do I have an issue with my wiring or is the issue elsewhere? It's doing my head in! The brake light filament on the original light is intact.

Thanks, Andy