Help troubleshooting electrical problem

Duncangog

New User
I need help troubleshooting what i'm pretty sure is an electric issue with my 1973 JD301A. I killed the engine rocking it back and forth trying to get it unstuck, and gave up for the night. It rained that night. Next morning I tried to start it and nothing, not even a click when I turn the key. It looks like it has a positive ground and I noticed there was a ground wire coming off the positive cable that was not connected (don't know if it ever was). I touched that wire to the metal lid and it sparked, connecting it did nothing. Tried jumping from my car, nothing.
I covered the tractor with a tarp and pulled the tarp off on sunny days, for about a week- still nothing. Put the battery on a charger and it seemed to take awhile to fully charge, still nothing. How do I go about trying to figure out what the issue is? Thanks- love this forum, learned a lot this last year, and got a lot more to learn.
 

Welcome to YT
JD 301A came from factory with negative battery ground cable. The negative ground was attached to the battery box. My guess is the area where rusty battery box & clutch housing touch probably doesn't have good continuity. I suggest to route a negative battery cable from battery to starter mounting bolt or engine block. I also recommend to have battery load tested.
 
Thanks- I guess it makes sense why what look like a ground wire off the positive terminal was disconnected. The battery was new this year so hopefully that is not it. I noticed the wires off of the solenoid are not great, cant tell where they run to/from the previous owner of the tractor apparently liked short bits of wire and electric tape.
 
Clean the connections to the battery, but also clean where the ground cable attaches to the tractor. Likely that's where the problem is. Good to do even if it isn't.
 
The negative post of the battery was already connected to the frame. I cleaned all terminals and connections from the battery, frame and solenoid/starter. -still nothing not even a click when I try to start it. I disconnected the negative battery cable and tested voltage between the battery and disconnected cable and got 12.5v. it seems like there should be no voltage when the key is not turned. battery is only 6 months old and seems fine (i brought it in and charged it). My next thought it to start pulling off the old black electric tape and rewiring everything (or at least start figuring out where the wires are going).
 

Having 12.5 volts between the negative battery terminal and the negative cable clamp with the key off, could possibly be a draw in the alternator. Disconnecting the alternator should eliminate that.

I would do some checking of what is getting power before tearing things apart. Have you checked to see what voltage the key is delivering to the to the solenoid terminal when you turn the key?

With your voltmeter on the battery side cable terminal (cables connected) of the solenoid, does the voltage drop when you turn the key to start? If so to what voltage?

When you were rocking it and it stalled, did you hit the key before things might have completely stopped and locked the starter drive into the ring gear. You may need to loosen or pull the starter to check.
 
Running the multimeter from the ground to the positive connection at the solenoid has no change of voltage when the key is turned (and clutch pushed in). 12.8 volts- no movement on the meter at all.
 
(quoted from post at 20:13:40 09/19/20) Running the multimeter from the ground to the positive connection at the solenoid has no change of voltage when the key is turned (and clutch pushed in). 12.8 volts- no movement on the meter at all.

You are referring to the terminal where the positive battery cable connects to the solenoid, correct?

When you turn the key to start what voltage does your meter show if you go between the small start terminal where the wire from the switch hooks to the solenoid and ground?
 
Hard to tell which wire goes where with the old wires all electric taped together, but tested everything off the solenoid with and without key turned - no change when key turned. The cable from the battery to the ground and right small wire was 12.8v, and 9.8v to the left small wire. ground to left small wire was 0.1v and ground to right small wire was 0.0v. There are 4 connections on the solenoid - top to battery, bottom to starter, and a right and left small wire to somewhere. Thanks very much for helping me- each time I go and mess with the wires and stuff I get more familiar with the machine.
 
(quoted from post at 17:01:23 09/19/20) The negative post of the battery was already connected to the frame. I cleaned all terminals and connections from the battery, frame and solenoid/starter. -still nothing not even a click when I try to start it. I disconnected the negative battery cable and tested voltage between the battery and disconnected cable and got 12.5v. it seems like there should be no voltage when the key is not turned. battery is only 6 months old and seems fine (i brought it in and charged it). My next thought it to start pulling off the old black electric tape and rewiring everything (or at least start figuring out where the wires are going).

Ground is connected to the frame where ?
 
The ground is connected to the frame just under the battery box to the bolt that holds the battery box to the frame. I cleaned it all up when i cleaned the battery leads/connections. they were in pretty good shape- previous owner must have replaced them in the last few years.
 
(quoted from post at 13:22:15 09/20/20) The ground is connected to the frame just under the battery box to the bolt that holds the battery box to the frame. I cleaned it all up when i cleaned the battery leads/connections. they were in pretty good shape- previous owner must have replaced them in the last few years.

Is that frame a main engine casting ?
The only ground connection that really works on those . Is to run a longer ground cable down to a starter mounting bolt .
 
Gas or diesel engine?

Does yours have a remote solenoid between the switch and starter solenoid? (Key switch operates the remote solenoid which in turn operates the solenoid on the starter).

Does your starter solenoid look like this one?

mvphoto62236.jpg


If it does do you have 12+ volts at the "S" terminal when the key is turned to, and held in, the start position? (shift levers in the proper neutral or park positions for starting)

Do you have 12+ volts at the bottom (starter connection) terminal of the solenoid when the key is turned to, and held in, the start position?

Tractor in neutral, try using a booster cable to jump from battery positive direct to the terminal at the bottom of the solenoid where the starter motor connects and see if the starter spins.

If it does not have 12 volts at the "S" terminal, be sure the tractor is in neutral and try jumping between the battery cable terminal and the "S" terminal with a jumper wire and see if it turns over with that. If it does you need to chase the wire back to the switch to find the problem. Among the things it could be (but not limited to) are broken wire, bad neutral safety switch, or bad ignition switch.
 
It looks exactly like that (without the letters marking it). It is a gas tractor. Connecting the cable from the battery to the "s" post the solenoid pops and the starter spins (it did not sound like anything else, ignition and such, was going). Connected to the starter directly and it spun. Thanks much.
 
Got it fired up and un-stuck! The actual culprit was the wire between the battery and the ignition/key switch, but there were a lot of wires that were cracked and hanging by a few strands, all fixed now. Thanks so much for all of the help.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top