The Fordson Tractor Pages Forum

any one know if dexta is pos earth or neg as i have 2 pos lead connectors, i think it may be pos earth

thank you
spike

think i foud it in the search looks like its pos earth

thanks
if i have it wrong just shout up please

spike

Originally Dextas were positive earth, however in a life of over 50 years some may have been converted to Negative earth. If you have an alternator fitted it will certainly be Negative earth.

To be sure and avoid burning out regulator and dynamo, with the wires removed from the back of the dynamo, take a wire from the Live Battery Terminal and flash it to the Small terminal (Field) on the dynamo. This will correctly polarise the dynamo to what ever battery terminal is earth.

Just to add to Brian's post, please ensure you correctly identify whether you have a Dynamo (One piece cast body with a bulge at the back to hold the rear bearing, One large terminal and one small (usually with nuts to hold the cable on) with a regulator inside the lower binnacle (the regulator is usually a large black body). The alternator generally has a body comprising multiple laminations of sheet steel with a plastic rear cover and Aluminium front casting with Large and Small terminals mounted in a recess, terminals parallel with no Regulator.
Only flash a generator.
cheers
Jerry

thank you, sorted poss earth, now i just need to fit the new front wheel bearings