Thanks John T.....yet I have another Question on Charg. Sys

John,

Another question......got the 140 troubleshooted and found a bad regulator. Thank you for the guidance.

I've got an IH 424 Deisel tractor with the same charging system (12 volt generator with regulator), BUT it does not have an ammeter. It only has a "dummy light". I noticed that the light remains on after cranking the tractor and stays on until you rev the engine and let the tractor run for a little while (about 2 minutes at half throttle). Once you let the engine back at idle, the light comes back on. I have reason to believe that the charging system is faulty somewhere. All of the wiring is original, untampered, and looks really good. I don't believe that is the issue. So tell me.....how in the world would I troubleshoot this charging system since it does not have an ammeter to let me know if it is charging??? Looking at the light is like a baby crying.....it can't tell you what's going on. Am I going to have to get out a multimeter, or is there another way to troubleshoot?? IF I have to use the multimeter, please instruct on where and what settings to use.

THANKS!

If theres no ammeter, another way to determine the charge rate is TO MEASURE THE BATTERY VOLTAGE. (DC Voltmeter on proper scale on battery terminals)

A good battery just sitting there with the engine not running ought to read around 12.6 volts (depends on battery, its charge and temp etc) HOWEVER with the engine running at fast RPM if coupled to a good working charging system and the Voltage Regulators Cutout Relay is closed as it should be, the voltage should rise to at least 13 volts and up to 14 or so subject to RPM, belt tightness and condition of genny etc.

When shes running temporarily dead ground the Gennys FLD post and see how she charges then ?? If it charges fine with FLD grounded but not as well or not at all otherwise, the VR may be bad (perhaps its relay contacts are burned or pitted or its mis adjusted),,,,,,,,,,,or the VR may have a poor ground CHECK THAT,,,,,,,,,Or the wire may be bad from FLD on Genny to FLD on the VR.......

If the charge is still weak even with gennys FLD grounded, the genny may need some attention such as: Brushes worn down short (typical),,,,,,,Commutator is oiled or carboned up (clean it) or pitted,,,,,,,,,,Brush hold down springys arent free and holding brushes down tight,,,,,,,,Fields may have problems,,,,,,,,Armature may have some shorts,,,,,,,,,,Bushings/Bearings worn.

Is the belt good n tight and not glazed????

Id check BOTH the Genny and VR have good grounds

May be possible to lightly clean/buff/polish the VR's relay contacts.

Try to clean up the gennys Commutator,,,,,,,,Insure brushes arent too short,,,,,,,,Check grounds (VR and Genny) and connections.

Heres my Troubleshooting Procedure

John T
John Ts Charging Troubleshooting

I really appreciate all the help John. Since I don't know anything about the internals of the genny.....how would you go about cleaning the brushes and commutator from carbon or oil buildup? How do you clean it?, where/what part of the generator are they located to clean, and what do you use to clean it?

THanks again.

If youre not experienced at all with Generators I just cant explain and cover it all in a few paragraphs here. You have to disassemble the genny by removing the two long pass through end cap screws, removing the brush end end cap, remove the armature with other end cap in place, clean/buff/polish the copper commutator segments (seperation insulation between segments may need undercut but Im not going into that here), insure the armature isnt shorted to the shaft, insure brushes are long enough, blow and clean out all the dust and carbon and oil etc etc. I use a light solvent (or whatever I have around) and shop rags and my air compressor blow gun etc but I cant describe all this on here, sorry.

HOWEVER dont be afraid, this isnt rocket science nor is the genny fragile, just use common sense and clean things up and clean off oil and carbon dust and insure the brushes and bushings and brush hold downs are all clean and working and theres no armature or field coils shorted TOO MUCH TO EXPLAIN IT HERE

John T

Thanks alot JohnT. If there was a Youtube video or photo guide on rebuilding/repairing/cleaning a generator, that would be VERY helpful. Maybe there is one out there somewhere. Would it be ok and benificial if I just used some carburetor cleaner, or electronic cleaner to spray the brushes, etc. through the dust cover?? If so, should I do it while running or not? Right now I'd rather not take one apart until I can be sure of what I'm doing. THANKS!

(quoted from post at 21:35:53 04/11/12) If youre not experienced at all with Generators I just cant explain and cover it all in a few paragraphs here. You have to disassemble the genny by removing the two long pass through end cap screws, removing the brush end end cap, remove the armature with other end cap in place, clean/buff/polish the copper commutator segments (seperation insulation between segments may need undercut but Im not going into that here), insure the armature isnt shorted to the shaft, insure brushes are long enough, blow and clean out all the dust and carbon and oil etc etc. I use a light solvent (or whatever I have around) and shop rags and my air compressor blow gun etc but I cant describe all this on here, sorry.

HOWEVER dont be afraid, this isnt rocket science nor is the genny fragile, just use common sense and clean things up and clean off oil and carbon dust and insure the brushes and bushings and brush hold downs are all clean and working and theres no armature or field coils shorted TOO MUCH TO EXPLAIN IT HERE

John T

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Spraying carburetor cleaner won't do the trick. You need to take it apart.

Really, it's no big deal. Two bolts and the whole thing comes apart. There is nothing to go SPROING! on you or come flying off unless things are REALLY bad. If they're that bad it wouldn't matter anyway you'd need a new generator if you took it apart or not.

The hardest part about getting it back together is holding the brushes out and away while sliding the armature back in place. An extra pair of hands makes the job easy, or some strategically-placed screwdrivers.

Ok! Thanks so much. I might just give it a try on an "extra" genny laying around.

Carb cleaner is a bit strong to just start spraying anywhere n everywhere randomly although some on a rag may be okay to clean the commutator once removed. Disassembly and a rag and some solvent and an air gun does the trick.

John T

Sounds like a classic "idiot light" setup you use on a 12 volt GM 10si alternator and 3 wire setup. The light stays on after start up until the alternator charges the battery back up from the voltage drop at start up. I'm no expert, but sounds like my Farmall 240 after I converted to a 10si and 3 wire setup. I've had no charging or starting problems. Not sure if your Genny is wired the same way.