The Fordson Tractor Pages Forum

Should a Major be Positive or Negative Earth?

Hey Craig, my Power Major is positive ground/earth.

Craig,

Original it's Positive Earth. Many change them in Negative Earth.

Thanks guys, I only noticed when I looked at wiring diagram!

Shouldn't make much difference, should it?

bluecraig0776 wrote:Shouldn't make much difference, should it?

If you make it negative earth, your headlights might shine black instead of white...

Ha ha

John wrote:

bluecraig0776 wrote:Shouldn't make much difference, should it?

If you make it negative earth, your headlights might shine black instead of white...

You mean they won't just shine backward .... But they will shine Blackward ..... I never told any of my bulbs what the polarity was so they don't seem to know the difference. Dandy Dave!

Hey Craig,

What ever polarity you choose, just make sure you flash the feild of the generator before you start it up, otherwise the lights may indeed shine black rather than white and you may have an expensive repair to your generator as well.

Regards, Frank.

Hi, just reading back on this old post as I'm about to install a brand new generator on the E27N.
Please excuse my ignorance but what does "flash the field" of the genny mean? Do I need to do this on a brand new one (I would say not).
How do I know whether to go with positive or negative earth?

Thanks guys,
Chris,

By the way, I do have headlights and hope for them to shine white and not black...

How are your battery leads wired up? This will, or should, tell you whether pos. or neg. is the earth. Usually the leads will only be long enough to fit on the appropriate terminal post.
Either way, no harm will be done if you go through the process of re-polarising the genny -- after you have decided which battery post to use as earth. Do this by removing [or not connecting] the inciter lead [the thinner one that operates the red ignition light], turn the ignition on and momentarily touch the genny terminal with this wire 3 or 4 times - it will spark each time.
Done!!
Pavel

Hi, thanks for the reply. I should've mentioned the tractor I am working on doesn't have any wiring at all at the moment.
It was bought as a wreck and has been totally stripped.
It's well on the way of becoming usable again though.
Chris