Basic Tractor Wiring - Question

Yesterday, apparently, while mowing with a rotary cutter, seems like something latched onto and pulled out the wire that is attached to a terminal on what I believe is a fuel safety shut off switch, small solenoid looking thing threaded into the bowl of the carburetor. In an attempt to re-connect the wire, Cliffy used a small screw and penetrated the top of the solenoid looking thing ! ( hole is next to the terminal that the wire was attached to). Well, I think that was a mistake, as I think he had to tow it up to the garage afterward.

This is where I started, kind of in the dark as to what was going on. I had done some neat repair to the wiring harness last winter for him, he was not well at the time and I think he had hooked the battery backwards and shorted,(fried) the alternator wire, it was burnt, everything else was fine, it apparently worked fine after that (good that we found that wire was fried and replaced it) he did say he thought the battery still had a draw on it up until yesterday. Hold that thought

So here is what I see in there, a 4 post Cole ingition switch, nothing turns over, battery appeared good, then not good, strange reading on my meter, tried jumping the ignition switch with 3 way jumper, turned a little then nothing, OK, well the switch seems recently fried and that battery has got some weird issue, acting just like having a bad ground. Get new battery, jump with 3 way jumper again, she turns over no problem. Got power to the coil, steady light, other side of coil flashing light, and it did fire slightly, very slightly though, but seems no fuel, after taking a whiff from stack after cranking, no I did not put my face over the stack, just checked to see if I could smell some vapors, this one runs rich when it fires up. I noticed the center rotor contact was worn, but it was running before this happened, will replace that and hold that thought just in case it too is or went bad at the same time as the rest of this.

Now remembering how easy it was hot wire older vehicles and such, like on an old Ford F series, 3 way jumper, pull the starter jumper after it runs, and thats it, figured we could get it fired up and diagnosed etc. On this 4 post switch, there is Battery, Ignition, Accessory and Starter. Battery to Starter, turns it over, and Accessory is no problem, lights come on, and like I mentioned I've power to the ignition system, so it's all pointing to lack of fuel. When I connect to that Ign post, it arcs, if I disconnect the gray wire to the fuel safety switch, it does not arc. This gray wire runs directly to the ignition switch, to the ignition terminal on the switch, and I assume it's meant to be powered when the switch is turned on, but now arcs for obvious reasons.

So after this lengthy description, would it appear that maybe the screw he put into that shut off switch screwed up the switch contact and it's now shorted, causing the the arc when I jump it at the Ign terminal on the 4 post plug for that Cole ignition switch ? I'm thinking this short also fried the contacts on the Cole Ignition switch as it was ok before the problem. That fuel safety shut off looks like something NAPA would have at their warehouse store.

Not sure about the battery draw, once we get it running again, I'll check the charging system, I forget how to find a draw again, had one on my F-600 and found that both the voltage regulator and alternator was bad in that case, the JD 2020 is 12V and I neatly repaired some frayed wiring, and looks like the rest of the wiring and connections are fine, most have been repaired, I'm very meticulous when it comes to wiring, connections etc. Kind of weird for me to be working on his tractor, but it's kind of the age where we need to look after our parents and help out.

You could have a fried resistor which may be in the ignition switch. At least my 4020 uses a 6 volt coil with a series resistor in the ignition switch or an iron wire in the wiring. That resistor is shorted by an auxliary contact on the starter solenoid to get better ignition while cranking.

You need a wiring diagram for the tractor to be sure and it may be in the parts book which you may be able to locate at JD Parts on line.

Many tractors have been made to run (probably a bit on the rich side) by cutting off the needle from the inside end of the shut off solenoid. There is a chance they will diesel when shut down hot or with the throttle open.

With knowing about the resistor and starter soleniod contact and that fuel shut off solenoid which has to have proper power for the engine to run, I don't know of anything else unique about the 2020 ignition system.

My neighbor's 2020 got hard to start in the winter and one day I went over and choked it really hard and it ran for me. The next summer I had borrowed it (and the neighbor) to use the loader as a work platform for some tree pruning and it got so it would only run at an idle and then only for a few seconds. Checking for fuel, I found none in the float bowl, but a good flow from the line when disconnected from the carburet inlet fitting. I removed that fitting and found a screen that was essentially plugged solid. I had 60 psi in my air tank and couldn't detect air flow through the screen. Deere didn't have a replacement so they drilled a hole in the screen, then after reassembly, the tractor ran fine.

Gerald J.

This one blows some black carbon when firing up and throttling up, I've spent some time in the seat on this one, makes me wonder if the needle has been cut and this now explains the slot in the end of that terminal connection of the fuel shut off with a 3/8's nut on it, is for the main jet.

Hopefully I'll figure it out, tune it up, I thought it was always running a little rich, wiring diagram will help, the ingition switch looks like it has enough room for a resistor, and seems to be bad.