24 Volt generator light on with Key OFF

Two people(bstover7 and dweitzel) have posted that their 24 Volt tractors have the generator light on with the key off. I cannot visualize how this is happening, especially since one of the people has unhooked every wire from both the key and light switch with the light still on! Several in the postings below speak of copper dust from the starter brushes contacting the starter case and connecting the case to the midpoint of the batteries via the small wire from the chassis to the midpoint. Granted this is a common problem that will drain the right hand battery and possibly burn out a bulb with the lights on. This situation needs to be corrected.

However, I do not see how this problem could cause the generator light to remain on with the key OFF! In normal operation, part of the key switch is fed from the left hand battery negative terminal to Bat A of the key switch via a wire from the starter solenoid. When turned on the generator light is fed 24 volts and the wire goes to the GEN terminal of the regulator then to the GEN(A1) terminal of the generator and then through the armature to the A2 terminal of the generator. A2 is hooked to a wire that indirectly hooks to the positive terminal of the right hand battery, thus completing the circuit for the generator light. Note) this is a 24 volt circuit with a 12 volt generator bulb. The 12 volt generator bulb is protected in the 24 volt circuit by a 50 ohm resistor in series with the bulb. On older models the resistor is in the switch itself and in the wire on later models. With this light unhooked from the key switch, I can't see how this light is staying on!

Here is a question: Left hand battery A (the one hooked to the solenoid and going to terminal A of the switch) also feeds the oil pressure light and the fuel gauge. These are 12 volt circuits that are fastened to the chassis and complete their circuits through the little wire going to the midpoint of the batteries. Obviously, when the switch is on, Battery A supplies both circuits. The question is, when the switch is off are the two circuits still connected to each other? I do not have access to a switch. If the two are connected, I could see voltage(12) back feeding from the midpoint of the batteries through the sending units of the oil pressure light and fuel gauge and then through the generator light to ground. This scenario if true would make the light grow dimly since it would only be 12 volts instead of 24 plus the resistance of the sending unit and oil pressure light. However if this is true, this should happen to all 24 volt tractors and it obviously doesn't. Also, unhooking the generator light from the switch should stop any back feeding.

If anyone has any ideas please respond as I am befuddled! Please don't respond with converting to 12 volts. Deere used this system on thousands of tractors for 11 years.

(quoted from post at 17:13:38
If anyone has any ideas please respond as I am befuddled! Please don't respond with converting to 12 volts. Deere used this system on thousands of tractors for 11 years.

Click to expand...

Just because JD built the 1010/2010 with a sorry diesel engine doesn't indicate one needs to continue to beat their head against a BRICK WALL attempting to overcome the engine problems.

Back when 24 volt system was utilized on JD tractors there weren't adequate 12 volt batteries & starters TO START DIESEL ENGINES as there are today. On any JD tractor that's not a restoration project(trailer Queen) that has 24 volt system I'll recommend to save the headaches/stress and change electrical system to 12 VOLTS.

I like 1010 and 2010 diesels. I see nothing wrong with them, for the time, except for poor parts availability.

First Deere engines to use positive valve-stem seals. First to use a wet sleeve deck. First to use USA rotary-distributor
fuel injection pump. May be the only Deere diesels to use a Ricardo Comet IDI system with glow-plugs too.

Jim, as a past used tractor dealer I'm NOT saying the 1010 2010 are good or bad HOWEVER I can say when they came across the auction block (in my area and experience) where dealers had to buy and sell to make a profit THEY TURNED THEIR HEADS AND THERE JUST WASNT AS MUCH DEMAND and prices were in comparison relatively lowwwwwwwwwwww. Sure some may have good luck and some bad luck with them as expected but dealers just didn't like to take chances on them IN GERNERAL there are, of course, exceptions.

John T

In my experiences working with the 1010 and 2010 series at three Deere dealerships - the engines were fine for the time. It was all the other aspects of bad design on the wheel tractors that drove us nuts. On the other hand, the crawlers were pretty good machines - even by today's standards.

I would still take a 1010 dozer over a 350 dozer that replaced it any time. I'd also take a 1010 crawler over a 440 crawler that the 1010 replaced. Great little machine. MUCH better reverser then any Deere crawler had previously. Also better track-frame system and better reverser-drive on the flywheel then the 350 series had until the D series came out.