Positive or Negative earth?

[G3L1946]

Hi,

Just going through my recently obtained 1947 G3L when discovered it is wired ‘Positive Earth’.
The handbook shows ‘Negative Earth’.
Why would this be? Were there changes made during production or was this changed maybe, by the previous owner? If so, why?

Regards,

Steve

[Groily]

Just a question of preference / choice really. Most bikes went pos earth in the '50s having been neg before (then things switched back to neg again in the '70s-ish).
If you want it neg earth, then it's a Q of 'flashing the field' by touching battery live (which would be the + side, for neg earth) to the F terminal of the dyn for a brief moment - or of running it as a motor off a battery with the neg side to earth and pos connected to bridged D and F terminals. Then swapping round the wires on the ammeter so the needle goes the right way.
If the voltage regulator is electronic, it needs to be of the correct polarity though. If mechanical, not an issue, works both ways.

[G3L1946]

Hi Groily, nice to hear from you again! So, from what you’ve said ,it makes no difference. I’m happy with that. If it works, and I know the polarity for the future, leave alone me thinks! Doesn’t really seem worth messing about with it.

All the best,

Steve

[Pharisee]

Remember the old adage... "If it ain't broke, don't fix it until it is."

[G3L1946]

Oh, so very, very true!

Steve