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Discussion Starter · #1 ·
Be gentle...I've researched the forthcoming topic to know that many threads have already been established on the subject. Is my question different? Or did I simply not find an answer that was satisfactory? here we go...

I recently purchased a partially restored (DC molested) Powermaster 851. I had assumed that by 1960, Ford would have been using a negative ground. So, being ignorant, when I inspected the tractor was not sensitive to the battery cables indicating a neg ground. The seller, IMO was likely ignorant too of the likelihood of a pos ground system when he replaced the 6v battery...hooking neg to chassis ground.

He informed me the generator wasn't working as the red dummy light on the dash indicated a charging problem. None of the other gauges seem to work either (Have no idea if he used 12v gauges or 6v gauges in his restoration?) I wasn't terribly worried about the gen problem as I got a good deal on the tractor.
Question one...might the generator begin to work simply by reversing the new 6v battery back to positive ground?

Question two...would any of the other components be damaged? Voltage regulator perhaps needing a polarity reset?

Question three...I'm likely going to convert to a 12v system anyway, the u-tube vids I watch DON'T mention anything about polarity of the system, only the instructions of how to hook up the wires from the alternator. It is assumed I'm sure that the 12v battery is neg grounded. As far as I know all 12v systems are indeed neg ground?

4,377 Posts
Hello and Welcome.
Some tractor manufacturers used positive ground well into the sixties even after starting to use 12 volt systems.
Most likely because electrons actually flow from a negative charge to a positive charge and regulated generators better.
Once alternators became the standard is when they all switched to negative ground.
Answer one.... It would be worth a try switch the ground then "flash the field" and see if it starts working.
Answer two.... It's possible that either the regulator or battery could be damaged if the generator was working when the battery was hooked backwards.
Answer three....If you plan to convert it to 12 volt with a Delco alternator then it would hook negative to ground.
One can find a positive ground alternator, but they are usually special order not inventoried by many auto parts dealers.
Light bulbs and electric powered gauges would need changed. The starter will work as is.
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