1953 M33 rigid - positive ground?

[Sigmund]

I am restoring this bike and wondering: how can I see if the set up is positive or negative ground?

[idie]

If you have a battery connect it positive to earth and switch on the lights and see which way the ammeter needle goes, it should show a discharge. If showing a charge then it's neg earth. Don't try this if it has a modern electronic reg. If it has the regulator will tell you which polarity it is. If it is a mechanical regulator this doesn't care which way it is earthed. If you want to keep positive earth and it is a mechanical regulator after connecting the battery just flash the F terminal to the live on the battery and this will re- polarise the dynamo. I would go to negative earth then you can easily source led bulbs to help the dynamo.

[Mike Farmer]

 

God that takes me back. Its a lifetime since I heard anyone talking of "flashing" the electrics to change polarity.

Mike

[Sigmund]

Thanks a lot, guys