Jet Star not charging

Donkeyguy5799 · Jul 22, 2023

Hi, we have a Jet star, it is not a number 2. As far as I know it has no number so maybe it is the first. It has positive ground.
It s not charging and I m trying to polarize it. It has a generator with regulator and it s 12 volt. I ve read multiple threads about touching field to battery, then I ve also read touching field to ground only as can damage regulator if touched to battery.
So my question is, it must be different polarizing if the tractor is positive ground ? Which one do I do with mine being positive ground ? Also, when the tractor is out in the field after it gets hot it barely runs. I had read a thread that it s possible if this tractor is not charging it can cause this. I can say that I don t like placement of the coil from factory so close to the block as it could get hot, but just looking for advice. Compression is good, valves good. Carburetor rebuilt by professional. Fuel supply I am investigating as the offchance rust in the bottom of tank moves when in the field, if any.
My main answer I m looking for is the 2 terminals to cross!
Any help you can provide will be greatly appreciated, thanks.

SWMolines · Jul 22, 2023

Try this.
Untitled URL Link

rvirgil_KS · Jul 22, 2023

To polarize your tractor momentarily jumper from hot battery voltage to ARMature post on generator. This can be done from BAT to ARM posts on regulator. ARM post should be on bottom of regulator. Polarize the same on positive or negative ground.

To check charging:
With engine running ground the Field terminal on generator. If this makes it charge you have a problem in the regulator side of voltage regulator.

If still no charge jumper from Armature on generator to hot battery. If this makes it charge you have a cut out problem in the regulator.

If still does not charge you have a generator or wiring problem.

If it were mine, before replacing a generator or regulator I would seriously consider changing to internally regulated alternator and change to negative ground. I have a 4 Star with alternator and would not change back to generator.

Donkeyguy5799 · Jul 22, 2023

thanks for your reply. I will copy and paste what somebody had said on here regarding the polarization.
" One word of caution though, don't short that field terminal on the regulator to anything but ground, i.e. Bat or A terminal as you will fry that new regulator in a heartbeat."
I m trying to make heads or tails of this. Is this different with positive ground?

rvirgil_KS · Jul 22, 2023

Positive and negative ground polarize the same. Both work equally well if configured correctly. It's like right hand and left hand threads on a bolt....current flows in opposite directions.

If properly configured your only concern is the generator regulator. Some are marked positive ground only, some negative ground only, and some marked either polarity.

Has to do with metal on the contact points. Will last longer if connected as designed.

This diagram may help you sort out the positive and negative ground...

molinegb · Jul 22, 2023

Theory is natural current flow is negative to positive. Positive being earth ground. Most tractors used until mid sixties. Supposedly created less corrosion
on cables?? Once alternator came out all were negative ground.

Jet Star not charging

Donkeyguy5799

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SWMolines

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rvirgil_KS

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Donkeyguy5799

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rvirgil_KS

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molinegb

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