Brake light doesn't work while sitting, once moving it works fine

[ducatilover]

For the tail light?
Deal.

Yes.

Wait.
No.

[EB255GTX]

you have already found that it's nothing to do with the bike moving, and it's unlikely to be to do with your battery/charging system as such - as long as you have enough charge to light up a bulb, you can test the wiring.

so it really should be as simple as: You have the bike frame, which is negative. you have 2 wires to the rear light, which are +12v when ign on (tail light wire) and +12V when either brake switch is on(brake light wire).

You say you have measured "all the right voltages" - is that zero when brake switches are off and around 12V when on? If so, put a test bulb on those wires, just any old bulb, sometimes one of the indicator bulbs that have short pieces of wire coming off them are able to be poked into the socket and make contact.

If the bulb lights up, then you know the new tail light cluster is the problem.

[DrunkenMistake]

Grabbed the tail light from mum and dads and banged in a new bulb, it is indeed the socket causing the drama, have tested on both sides of the plug and all the readings are correct, come to the socket and I have 12.9 on two pins and nothing for the third, (with the break lever on).

cheers for the help