Neg or Pos Earth


New Member

I am checking to see if my 1959 P4 75 would be negative earth or positive earth please. I do not have aceess to the car at the moment to check where the leads go to so any help appreciated


  • IMG20230530134002.jpg
    2.3 MB · Views: 12
It would have been positive earth when new, and looking at the leads in the picture, the negative is routed through the armoured conduit to the front of the car , it is still probably positive to the frame . I would double check just to make sure there are no modifications outside the scope of the picture.
I have seen conversions to neg earth work fine except for one issue - if the coil terminals are marked '-' and '+' they can be polarity sensitive - make sure these connections are correct polarity.
it would of been postive when new, but impossible to say now, in my experience most cars have been converted to negative earth