JD 420 Tractor Generator

[bsekf]

The generator isn't charging the battery, it could be a broken or loose wire. Or it could be the generator. Is there a simple way to check to see if the generator is charging? I am eclectically challenged, so please keep it simple.

Bill

 

[Roadworthy]

Check your battery voltage. Start the tractor and at a high idle check the voltage again. An increase in voltage will indicate the generator is putting out. Clean all connections at the battery and reinstall cables tightening securely. Follow ground wire to frame then clean and tighten there as well. Eliminate the basics before beginning troubleshooting.

 

[DJ54]

If the above procedures doesn't help the situation look in your area for a starter/alternator/generator rebuild shop. They can bench test it so you know for sure. Probably not a bad idea to have them freshen it up with new bearings & brushes.

That being said, I assume the 420 is a 2 cylinder model, being you are saying it's a "generator", not an alternator.

In all honesty, your problem could very well be the voltage regulator. If that is the problem, I highly suggest going to the John Deere website, and look up the part number for that VR. Then, cross that part number to a VR made by Standard Motor Products. DO NOT even bother with one from Tractor Supply, or even NAPA. You'll be lucky for one of theirs to last a month, if that long.

I've looked for years to find a good "Made in U.S.A" VR for my small Farmall tractors, and finally found the ones that are made by SMP. The oldest one I have has been on the tractor for going on 4 years now, and still works like a champ.

If your generator does have problems, and needs repair, when re-installing, don't forget to re-polarize it. A simple procedure that you can find instructions to online.

 

[DJ54]

Again, if it is in fact a generator with a voltage regular, I went ahead, and went to John Deere, and found the regulator needed. https://partscatalog.deere.com/jdrc/sidebyside/equipment/67961/referrer/navigation/pgId/173826 OEM is an AC-Delco P/N 1119575. This crosses to the same SMP VR used on my small Farmall's. SMP P/N VR-214. Ecatalog

Many auto parts stores carry them, but I've gotten the last 5 off a vendor on ebay, if you dabble any on there. He buys in bulk and passes the savings on. He can be $30 to $50+ less than other vendors, and offers free 4 day shipping. SMP VR214 NEW Generator Voltage Regulator | eBay

 

[bsekf]

Is there a way to check at the generator? Even if the regulator is bad the generator should put out voltage but it wouldn't get to the battery. Right? I was thinking of using a test light, but not sure just how. Keep in mind, I'm eclectically challenged.

 

[DJ54]

There is a procedure called "motoring" a generator. Never tried it myself, all it really tells you that it is working. I prefer to take it to the starter/generator shop, and have him bench test it, and see how well it's working.

 

[dieselade]

get a little hand held gizmo that checks voltage. auto parts store should help you. main thing is you want to check volts at the battery terminals. tell them you want one to check 12 and 6 volt batteries. nice ones have ohms and can check house voltage also.
if not charging over 6 volts, then you start checking wires. also check the for dirt on the armature grooves that the brushes ride on. and or do what others said find a shop that checks this.