Positive Earth?

[Arthurdaily]

Hi, can anyone tell me whether my standard 67 moggy is positive or negative earth? ... And then what that means ha ha!

[simmitc]

Look at the battery. One thick wire goes to the starter solenoid, the other (usually a braid) is bolted to the body. To which terminal is the body connected? If it's marked + then it's positive earth, if it's marked - then it's negative.

As standard it would have left the factory as positive earth (with a dynamo), but many have been changed to negative over the years.

How good are you on electrical theory to understand the difference?

[Arthurdaily]

Hi, the postive terminal is attached, via a little terminal box, to the starter. The negative is attached striaght to the body. So, it is negative earth like a modern car yes? I.e. to attach a modern piece of gizzmonatry, like a radio, one would earth the chassis of the radio to the body of the car and then attach a POSITIVE feed from the main fuse box?

Interesting, as I'm presuming the green dynamo thingy is still a dynamo, and not an alternator - is that bad in any way to be using an original dynamo in a negatively earthed car??

My electrc basics are 'okay', I don't electrecure myself or anything... but theory is difficult if I remember from school... lol.

Damn... the fact it has been altered to negative earth will make understanding the Haynes book of trickery even harder won't it!!!

[mike.perry]

There is no problem with a neg earth wired dynamo, in fact it is better as there is less electrolytic action on the wiring terminals.
Wiring diagrams will be exactly the same unless it states pos or neg.