Triumph 3T 1950

[den]

Hi I am new to this forum and new to vitage bikes (last time i had a vintage bike it was nearly new) I have just purchased a Triumph 3t and need some help with the electrics. 1 Should this be positive or negative earth? 2 I cant seem to get the dynamo to charge the battery.The ameter is not showing a charge at all.3 does anyone know where i can find a wiring diagram? I have brought an instruction manual which is an original 1950 booklet and whilst there is a good ammount of info on most aspects there is no wiring diagram.
Lastly the stop button is not working so the only way i can stop the engine is by stalling it. I have had the button out and disconected it and tried crossing the wires but this does not wiork either so it is not the actual switch.
If anyone can help with any of the above i would be very grateful.

Thanks in advance

[Revband]

Hi Den

In 1950 it would probably have been negative earth, but you can wire it either way neither the dynamo nor the cut out unit are polarity sensitive.

Check which battery lead is connected to earth, assuming the negative is, disconnect both the F & D wires from the dynamo then using a length of wire connect the battery positive to the F terminal on the dynamo for a second or two (if positive earth connect the negative battery), this is known as flashing and the wire will spark when touched on, doing this will re magnetize the field coil core, next connect a volt meter between earth and both F & D on the dynamo linked together, start the bike and you should get an output from the dynamo dont over rev the bike as the voltage will rise rapidly if you do, keep it under around 12 volts, this will show whether the dynamo is working if it is reconnect the F & D leads and start the bike again to see if all is now OK if not then you have a wiring or cut out fault.