JD 50 electrical staring issue

Tried starting my 50 after a long winters nap, started turning over fine but the battery was wearing down so I put the charger on it in the jumpstart position and then nothing. Totally charged up the battery and had it load tested, good 600+ amps, next changed both the negative cable to the starter and the positive ground cable, 12 volt system. Still nothing, replaced the push button switch on the starter, no joy. The weird thing is if I hook some jumper cables to the battery, put the negative on the starter bolt and attach the positive to the frame to ground I can get the starter to spin up but not enough juice to engage with the flywheel, 12 foot long 10 gauge cables. I am now stumped as what to check next. It is my understanding that the starter grounds to the frame via the bolts that attach it to the frame, could this be the problem
 
I think you lost your ground between the seat frame and the rest of the tractor. Some tractors I just run the ground cable close by the starter.
 
The "spin up" you are creating by connecting direct from battery to starter will never engage the starter with the flywheel because the engagement function is totally mechanical and occurs when the starter "button" is depressed. The downward motion of the starter button pushes down on a yoke that pushes the starter engagement gear into the flywheel and closes the "button switch" that you replaced on the starter.

Hope this explains it OK.
 
"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">changed both the negative cable to the starter and the positive ground cable, 12 volt system. Still nothing, replaced the push button switch on the starter, no joy.[/i:654c4848f0][/b:654c4848f0]</font>"

Since you installed new battery cables, check the end of the ground cable where it is bolted to the frame.

Make sure it is making good connection with "clean" metal.

Using a test light, check the end of the cable connected to the starter switch on the starting motor for a good connection.
a256179.jpg" width="650"


If the light shines, then the ground cable and power cable are making good connections.

"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">The weird thing is if I hook some jumper cables to the battery, put the negative on the starter bolt and attach the positive to the frame to ground I can get the starter to spin up but not enough juice to engage with the flywheel,[/i:654c4848f0][/b:654c4848f0]</font>"

[b:654c4848f0][i:654c4848f0]<font color="#ff0000">CAUTION: Before you begin this troubleshooting step, make sure of the following:

Lock both brakes.

Shift the transmission into NEUTRAL.

Turn the ignition switch to the OFF position.

Remove the coil wire from both the coil and distributor.

Turn the gas off at the fuel filter.[/i:654c4848f0][/b:654c4848f0]</font>

If there is power at the starter switch, then push the button to engage the starting motor.

If the starting motor does NOT engage, then remove the new starter switch and check for wear on the stud terminal on the starting motor.

Inspect the stud terminal on the starting motor.
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If the stud terminal is severely worn, then it may not be making a good connection with the starter switch on the starting motor.

Hope this helps.
 
In these types of starting problems my approach is:

FIRST Insure a good full charged battery of adequate capacity.

1) Remove, clean and wire brush, inspect each and re attach every battery post and ground and starter switch connections. Insure cable ends are secure, I have observed some crimped connections look good to they eye outside but theres carbon and burning (bad resistive electrical connection) inside from the wire to the terminal.

2) It can help (in some situations) if you re attach the frame ground cable to a clean bright bolt/frame located near the starter versus a thin or rusty sheet metal seat connection.

3) Insure the saddle mount starter switch is getting fully downward depressed when activated.

4) I have seen the starter switches go bad (carboned burned pitted contact) and/or the copper post out the starters side get burned and pitted and needs replaced.

5) A weak battery or a bad resistive connection or ground can cause low voltage to the starter which can cause it to spin too slow to engage and crank properly.

6) If when trying to crank the battery voltage drops drastically you could have a faulty starter or a stuck/jammed starter or a bad battery, but if the voltage doesn't drop much and still no cranking, you could have a bad cable or connection or ground or bad starter switch, or again a bad starter. Look for smoke or listen for sizzling lol

Once you have a good full charged battery, check all cables and connections and grounds and starter switch and side starter post located under the switch....

Hope this helps

John T
 
The ONLY rational, intelligent way to diagnose electrical problems is with a voltmeter. You can't see electrons, so "looking" at cables, connections and grounds is just a time consuming, expensive way to diagnose problems. You can buy a voltmeter at a place like Harbor Freight for around $10. The 50 has a foot operated mechanical starter switch. and came from the factory with positive ground so you will need an assistant. Place the negative lead of the meter on the center of the negative terminal of the battery and the positive lead on the starter terminal. WHILE CRANKING you should read less than about 3 tenths of a voltage drop. This is the voltage lost in the cable and connections from the negative battery terminal to the starter. Next, put negative terminal of the meter on starter case and the positive lead on the center of the positive battery terminal. WHILE CRANKING you should get 3 tenths of a volt on the return side of the circuit. The objective is to lose the voltage in the starter itself rather than getting to and from there. If these readings are ok, If would look at the mechanical switch on the starter and the copper terminal of the starter itself. If everything checks out the starter will have to be taken apart. For more information call "Green Magazine" and ask for the article entitled "My Tractor Won't Crank" which I wrote for the November 2012 issue. They will send you a copy of the article. Let us know what you find.
 
. Thanks for all the advice ,it was not grounding from the seat box to the frame. Put a ground cable from the positive terminal of the battery to a frame ground and it fired right up
 
(quoted from post at 18:04:06 04/14/18) . Thanks for all the advice ,it was not grounding from the seat box to the frame. Put a ground cable from the positive terminal of the battery to a frame ground and it fired right up

Hmmmmm..... The very first response you got...
Glad it was something simple, and that you got it figured out.
Thanks for letting us know!
 
yes Matthies was right on with what was causing the issue, I owe him at least a good lunch,lol. Why are the simple problem always the toughest to fiqure out
 
CONGRATULATIONS Lots of agreement below regarding a possible bad "seat" ground. As a used tractor dealer I saw that happen sooooooooooooo many times and so many wise gents ran a ground cable down to the starter area to cure that common problem.

Glad to hear you get her going, thanks for the feedback

John T
 
If you had used a voltmeter and the procedure I described below you would have found the problem in 5 to ten minutes. I have seen people buy battery, switches, cables, and a starter only to find they had a bad connection. Cables are tricky as I have seen new looking cables having a voltage drop. Conversely, I have seen awful looking cables and connections that were fine. The voltmeter will find the problem IMMMEDIATELY with a great saving in time and expense.
 

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