Can anyone tell me if the three pin starter relay on a 73 sportster should be earth (ground) free? I have a four pin fitted with a negative to ground on one of the coil wires. This introduces a ground via the positive as soon as the starter button is pressed. Doesnt seem right to me!

 

i don't think it does.. here's a link to the wiring on this bike.

 

Thanks for the link. The relay on that drawing is definately earth free. Must be current sensitive rather than a straight pos - neg arrangement.
Found two wiring looms so far and numerous chopped off ends.
Full re-wire is my best option! Gotta be right then!

Thanks very much, most helpful