40c neg ground

[sunnyfield]

my 40 c has a neg grd and the gen. is not hooked up .If I make it a pos grd will that hurt the starter ?I would like to get it charging again also

[JD440ICD2006]

Check the voltage regulator to see which orientation it is. Only if it is both POS and NEG can you run it the way you want. Otherwise, you must run the way that is stamped on the bottom of the VR.
For average usage, I don't think it will matter to the starter.
Be sure to polarize the generator after everything is hooked up correctly.

[DMarsh]

Several years ago I converted my old 6 volt Furgason tractor and 6 volt John Deere 420C from positive ground to a 12 volt negative ground with no conversion to the original starter. The only difference is they start much better. The reason that works is because they are not permanent magnet motors. When the current flow is reversed it reverses the magnetic field in the armature and the field so the motor still runs the same direction. Do be careful about the regulator and generator connections. I installed an automotive alternator. I know It doesn't look original but my equipment is to use not for show. I kept the old parts in case I ever sell it.

[JD440ICD2006]

There is no contest between a generator/voltage regulator hook up and an alternator. We all know that an alternator charges great even at idle, and has it's own regulator.
With that said, I personally prefer originality. An alternator is an upgrade or more modern way to charge the batteries.
If I wanted to upgrade, I would not only cobble an old ugly alternator on to my tractors, but I would also add digital gauges, Xeon headlights, etc.
I run generators on all of my tractors and do not have charging or starting issues.
It is a personal preference but I never bought the excuse that generators would not do the job. If they are wired and set up properly, along with a good battery, they work.
On my M's, I still have 6 volt positive systems with cut outs. The correct switch is in the dash so I just need to change from high charge to low charge after running a while. To me, it is all about having antiques tractors.

[rvbarkley]

Not mentioned yet, going from 6 to 12 volts, is the risk of damage to the starter or ring gear from the 6 v. starter engaging harder.
A 6 volt system, in good repair, should give no trouble starting and charging, as they have for the last 60+ years. JMHO

[Lavoy]

If you were going to go to 12 volt for sure, and use the crawler much at all, I would have the starter converted to 12 volts, then there is no damage issue with the increased cranking speed.
Lavoy