Help needed

[boilermaker1]

I fitted brake light to my (US) 400 f today
One filament of the bulb is on all the time
But pressing either brake does not light the
Other filament ... Both brake switchs appear
to be working,, I checked the switches with a
continuity meter,, where do I start trying to sort this???

[petermigreen]

As Oddjob says but I’m not sure the tail light is permanently energised on a US bike. I think it may only be the front indicators (low wattage) and headlight (low beam/pilot). I rewired mine to UK spec early on and can’t remember the tail light as such.
Peter

[boilermaker1]

Thanks for the replys, very helpful
I realise I did not fit a third wire to
the body of the light 
Will check over weekend