D10 12 volt, positive or negative ground?

Probably positive ground if original. You should be able to look at battery cables and tell. HTH Tracy

Ii dont have a D10-12 diagram... but your will look REAL CLOSE to this...

Thanks for the reply, but both cables are homemade and have same end on them. The ground cable even attaches to the small side plate where the D10 decal is, they just drilled a hole in the sheet metal and divided the wire in 2, about 3” from the end and run a bolt through the wire, no connector at all. It did not have a battery in it when I bought it non running, it had set 30 years in a barn according to the owners son who sold it to me, and he had no clue.
I now have it running and everything working fine. It’s time to turn my attention to the wiring and gauges and charging system. It came 12 volt so I’d like to keep the original generator. May need rebuilt, not charging now. I’ve had battery hooked up both ways, still runs just no charge.   
Will probably start on it soon, just didn’t want to rebuild generator and then hook it up to the wrong ground.   

Start up the tractor and GROUND the "F" terminal on the generator and see if the amp gauge works..

It was originally positive ground, but that doesn't mean someone hasn't changed it. The way to be sure is if the battery ground is positive, the coil wire going to the distributor must be positive.

The first D-10 and D-12 (1959, 1960) that some folks refer to as Ser.I, were 6 Volt.
The 12 Volt started with the Ser.II in 1961. All Pos. Grd. with a Generator.

G

I have a '65 D10 and it is positive ground. Cindy's Alternator and Starter in Fayetteville, NC does great work if you need it, and has rebuilt my original starter when it burned up. 

Edited by Aaron W in NC - 11 Mar 2023 at 4:44am