I have a 1955 Fordson Major diesel 4 cyl tractor. The battery was removed and I want to put it back but wonder is the tractor positive or negative earth? Does anyone know?
Thanks
Dawn
North Wales

Dawn, February 2008

A tractor of that age would be positive earth, your battery leads should have plus and minus stamped on them, also the battery will also have plus and minus on it, the plus is always larger diameter, the positive cable should be earthed on to the tractor somewhere and the negative should be attached to the solenoid. To be sure it hasn't been changed, take the wires off the Dynamo, connect the battery up as I said and get a piece of insulated wire long enough to run from the battery to the Dynamo, connect one end to the negative terminal on the battery and rub the other end on the smaller of the two terminals on the dynamo for around 5 seconds, this will polarise the Dynamo, then refit the wires to the Dynamo, then remove the wire from the battery.

Parahandy, February 2016

it is a pasitive earth. well it is on my fordson major.

George, April 2009

If the leader with largest diameter on battery adaptor is connected to the starter, then it is negative earthed, and vice versa. OK ? The minus on the battery has smaller diameter.

Jon , Norway 1956 Fordson Major Diesel Mark I, August 2008

The battery go's to positive earth, hope that help's you.

anthony, July 2008

If you have a dynamo you can use +ve. or -ve. earth as long as you polarise the dynamo accordingly.

With the dynamo unplugged, take a jumper lead from the battery live (non earthed side) and flick it across the "F" terminal a few times.

If an alternator has been fitted (I did) then you must use -ve. earth.

Mr. Toad, July 2008

Fordson Majors were definitely Positive Earth. If you want to use an alternator for better charging you can change them to negative earth quite easily.

Chris, April 2008

The fordson major diesel & power major are both shown as positive earth, in the old twenty repair manal wiring diagram.

phil murat, February 2008