Generator won't adjust below 8 amps

39 Ford 9N, 6 volt generator (9N10000C). When the battery is fully charged and I adjust the output to the lowest setting it is still putting out about 8 amps. From what I understand this isn't a good thing, what inside the generator actually causes this condition?

Does the adjustment work at all?
75 Tips

Yes the adjustment works, I can make it go higher if I turn it up but it won't go below 8 amps at its lowest setting.

What is the battery voltage when it's charging 8 Amps?

It is POSSIBLE the battery is "bad" (weak/shorted cell) rather than a generator issue, IMHO.

Re what Bob just said.......check your battery.

See tip # 49.
75 Tips

(quoted from post at 11:45:41 03/22/18) What is the battery voltage when it's charging 8 Amps?

It is POSSIBLE the battery is "bad" (weak/shorted cell) rather than a generator issue, IMHO.

Click to expand...

I let it warm up for a while and the current was at 9 amps at a voltage of 8.5 volts. I'll pick up a hydrometer tomorrow and check it. The battery is only 7 months old although I realize that probably doesn't mean much these days.

(quoted from post at 19:14:16 03/22/18)

(quoted from post at 11:45:41 03/22/18) What is the battery voltage when it's charging 8 Amps?

It is POSSIBLE the battery is "bad" (weak/shorted cell) rather than a generator issue, IMHO.

Click to expand...

I let it warm up for a while and the current was at 9 amps at a voltage of 8.5 volts. I'll pick up a hydrometer tomorrow and check it. The battery is only 7 months old although I realize that probably doesn't mean much these days.

Click to expand...

...what inside the generator actually causes this condition?" The adjuster screw has a gear on the other end that turns another gear which moves the third brush closer or further from one of the fixed brushes and that brush position determines the generator output. Perhaps dirt/corrosion has impeded full travel of the movable brush?

The original 9N-10000 A & B generators only had an output of 7 amps. The 'A' is a 2-wire/2-brush unit using a rectangular voltage regulator; while the 'B' unit is a 1-wire/3-brush unit having a black button on the back panel for "HI-LO" 3rd brush adjustment and now used the round-can cutout. When the 9N-10000-C generator was released, output now was at 11.5 amps, slider button replaced with a screw pot for 3d brush adjustment. Now, don't assume your generator is wired correctly. It may have been set with only 2 brushes with no 3rd brush at all, and wired for output at 7 amps. You'd have to open it up and/or have it serviced by someone who knows Ford Tractor generators. How about belt tension? Do you have the belt tensioning device attached and set properly? Sloppy belt tension is like a one-legged man at a butt kicking contest. The 3rd Brush adjustment was designed to be increased whenever the headlights were used, backed down when not in use so as no to overcharge the battery. Next step is to verify all the wiring. Your original 9N/2N Owners Manuals and the I&T F-04 Manual will have the schematics. Get a copy of "WIRING PICTOGRAMS by JMOR" and locate your setup, then start tracing wires. Lights can be disconnected just to take them out of the equation, can be reinstalled later. You made a good call by starting with battery too. Get it checked at your local starter/alternator shop as they have the right test equipment to do so. Battery must sustain a charge under load to be efficient. Yes, it is also correct that just because a battery is relatively "new" does not mean it is a good device. Bargain-house batteries usually only last 2-yars on average, and some are bad out of the box. Also, if they freeze, they become junk and the same if they get overfilled and boil out all the electrolyte. Invest in a quality brand battery if old one is bad and start there.

Tim *PloughNman* Daley(MI)

I tested the battery today with the hydrometer and it tested good. The battery shows no sign of weakness when cold starting either. Seems like there must be something going on inside the generator. I can adjust the current in the other direction meaning make it go higher but I cannot get it below 8 - 9 amps at the lowest setting. I don't have any lights to use some of that current either. I also don't have a belt tensioning device on the generator but the belt is tight and if it were loose you'd get less current output, not more.

I should probably open up the generator and see what's going on inside there at this point.