Scooterotica

just finishing wiring a new lamby up 12 v convertion -AC front lights work fine horn fine back brake light fine -- but no back light --

the weird thing is if i take earth out from front light back light come on - tried a new igintion switch does the same -- any ideas -- the next thing i think is a new front bulb holder -- seems to be zapping power some how when earthed anyone had the same

Are you using an Indian ignition switch with an electronic loom? If so you need to connect the purple (blue on some switches) to the browns in the headset otherwise you will get the symptoms you describe.

yep sorry should have said

It seems it has a blue i tried adding it with the browns -- i get no lights at all or horn - but when i add that blue with the blacks i get at least the front lights horn etc

You have re-earthed the front light?

yep the earth for the front light is earthed to the handlebar rod bracket

I think you need to go over your wiring again. The brown and blue switch wires are both power feeds into the switch.
The blue provides power to the pilot (via yellow), speedo and tail light (via the blacks) when the key is in positions 2 & 3.
The brown provides power only to the main headlight (via the orange) when in key position 3.
If you are using an electronic loom then to get power to both circuits the brown and blue must connect to the brown loom wire(s).

i will go over it over on the weekend and report back thanks for your help

does the back light work on key position 2 but not 3?

If so, then had same problem and was told it was a bad batch of indian ignition switches, incorrectly configured (is there any other kind? ).

Got a CASA switch and all was well.