JD 40t Won't turn over... Not sure what I did. Please help

Ok. So a little background. This was my fathers tractor. It's been sitting under the shed for 14+ years. Now that I'm Married and back home I've decided to get her running again. I had her running good all until a few hours ago until I removed instrument panel to see what all I would need to replace a few gauges....everything was very corrosive. So I put panel back in and assumed everything would be fine, but when I go to start her I get nothing..no noise..nothing. I have a new ignition light switch otw. Is the switch my problem or did I fry something else? Thanks in advance. I don't know much about tractors but I'm learning a little now.

This is a John Deere 40t.

Btw.. To get her running I replaced battery spark plugs and points/condenser. Then checked my timing. Also rebuilt the carb. That got her running pretty good. But then I got too excited and that's where I'm at now

"<font color="#6699ff">[b:654c4848f0][i:654c4848f0]Is the switch my problem or did I fry something else?[/i:654c4848f0][/b:654c4848f0]</font>"

Take a look at the diagram below.



Note the [b:654c4848f0]Red[/b:654c4848f0] wire from the Starter Switch to the POSITIVE post on the Ammeter.

Note the [b:654c4848f0]Black[/b:654c4848f0] wire from the Regulator to the NEGATIVE post on the Ammeter.

If your Model 40T has a generator as displayed in the diagram above, then the ammeter will be "wired" as shown above.

If your Model 40T has been converted to a 12V NEGATIVE ground electrical system and has an alternator, then your ammeter will be "wired" as shown in the photo below.



Note the [b:654c4848f0]Red[/b:654c4848f0] wire from the NEGATIVE post on the ammeter to the "BAT" post on the new ignition switch.

Remove the instrument panel and check for any "loose" or broken wire connectors.

You might consider using a test light to check for electrical current at both the POSITIVE post on the ammeter and then the NEGATIVE post on the ammeter.

If there is electrical current at the NEGATIVE post, then the ammeter is good.

Take a look at the photo below of a new ignition switch.





Check for electrical current at the "BAT" post on the ignition switch.

If there is electrical current at the "BAT" post, then turn the ignition switch [b:654c4848f0]ON[/b:654c4848f0].

Check for electrical current at the "ING" post on the ignition switch.

If there is electrical current at the "ING" post, then the ignition switch is good.

If the electrical system is the original POSITIVE ground, then check for electrical current at the NEGATIVE post on the coil.

If the electrical system has been converted to 12V NEGATIVE ground, then check for electrical current at the POSITIVE post on the coil.

If there is electrical current at both the POSITIVE and NEGATIVE posts, then the coil is good.

Hope this helps.

Sounds like you're well on the way to getting you dad's tractor back in good shape.

Hope you enjoy your <a href="https://youtu.be/ufkD9Do7Gf8?list=PLCUEeGboEbi-pR6w2onO-9zclH9sBoDVu">Model 40T</a> as much as we enjoy ours.

If I'm reading your post correctly the starter isn't working? IF the battery is still charged most likely you lost your ground connection while working on the dash. The ground cable attaches to the dash, travels through the rust at the bottom to the torque tube and then to the engine. Life would be simpler if you used a longer ground cable and attached it to the starter. The origonal connection works great if you lift the dash, clean the rust and apply dielectric compound to the mating surfaces. If it isn't the ground it's the starter switch(on top of the starter) or starter(rarely the starter).

James, Super response. Love the video. This is why I read the discussion daily.

Glad you enjoyed the video; it is still one of my favorites.

Thanks James!!! Pictures are great as well as the video. I do happen to have the service manual. Granddad was the manager at the local John Deere ages ago. Its been a great help.

After looking at everything again I'm really surprised it turned over to start off with. I have not had a chance to check power at switches yet, I should have time by the end of the week. I will try and post pictures so anyone interested can follow along. Thanks again

Hood, Grille, and lights are still under shed, but this is how she sits right now..she needs a little TLC.

I got here late but I kind of like M Mans analysis FWIW. If you run a good dedicated heavy battery ground cable from the battery + to a clean bright shiny bolt to the frame member NOT ANY THIN WIMPY RUSTY SHEET METAL see if that helps. Heck even try a jumper cable from battery + down to the frame or engine near the starter.

NO a faulty ign switch doesn't carry heavy starter current from battery to starter, it just handles smaller lights and ignition loads.

Those starter switches can go bad from burning and carbon and pitting causing no starter cranking but Id insure a good frame ground is present first and the battery well charged.

John T

So I'm guessing I don't need 6v dash light, hour meter or cigarette lighter hooked up?

I have not tested power to switches yet. I'm waiting on parts before I start tearing things apart.

Will update again soon