JD 3020 24volt light/short question

[bstover7@hotmail.com]

I completed installation of a new 12 volt battery, hooked the 2 12volts in series (right battery negative to left battery positive) and established a positive ground off the left battery. Vola, the lights worked..until I started the tractor. I did some reading and polarized the generator by momentarily connecting the batt to arm/gen contacts on the regulator. No dice. Volt meter show -24volts at the regulator and starter. Is this reverse polarity normal? The gen light also has come on, with the key off, when the positive ground is attached. It goes out when I disconnect the positive ground, so I think there must be a short in the system?
Any advice, other than 12volt conversion?

Thanks again!
 

[JD Seller]

The JD system is not a true 24 volt one. If you have your batteries hooked in series they are not wired correctly. The original wiring would have the none grounded cables going to the TWO different terminals on the starter. The starter was the only thing that saw 24 volt power.
 

[Olliejunkie]

Did you put a fusible link to the chassis on the cable that goes between the batteries?
 

[bstover7@hotmail.com]

I have attached two possible wiring diagrams for the 24volt 3020. I had understood, although I'm quite possibly wrong, that the colored diagram was for later models and the other (which I believe is the way you are referring), was the original system?

I'm open to advice,

Thanks!!
 

[bstover7@hotmail.com]

No I did not. My understanding of the fuse is that it will protect the lights from blowing from the 24volt load in case of a short? I have disconnected the 12volt system because I don't have fire insurance...although maybe I should get some and hook it back up:)
 

[JD Seller]

Yes there are early and late model wiring differences. You have it wired to the early diagram I am assuming??? So it is kind of a 24 volt system as they are just hooking the 12 volt side at the starter rather than the fusible link at the one battery.
 

[Bob]

[Olliejunkie]

[bstover7@hotmail.com]

Bob,

Thank you. I will put all your suggestions to use tomorrow and let you know how it goes.

Bruce
 

[bstover7@hotmail.com]

Great. Just to be sure, the updated diagram is the black/white one I posted a picture of?

Thanks!


Bruce
 

[Olliejunkie]

I think I mis spoke. I believe I ran a cable straight from one battery to they other and then attached the fusible link to it. Now you have me second guessing wether it's right or not.
 

[JD Seller]

Bob I am wondering if he has the two cables on the wrong terminals on the starter??? You have told him the correct way to check it.


To clarify my statement about the system not really being a true 24 volt one and that the starter is the only thing that sees the 24 volts. This system is not a common 24 volt one like you find one the majority of military vehicles. I will stand corrected in that the Alternator sees the 24 volts as well as the starter. The rest of the system just sees 12 volts. Either positive or negative ground.

Long story short. The system works fine when it is working. When it does not then if one of the two major components, starter or alternator, are bad then I would recommend switching it over to a 12 volt system.
 

[Tx Jim]

bstover
If small ground wire isn't completing connection from rear LH battery post to frame then gen light shouldn't be "on" as it should have no 12 volt ground without small wire making connections. If generator light is on when ign switch is off something is back feeding gen light which is probably the volt regulator at fault.

What do you imply when you state "you have no fire insurance"?? Does this 24 volt system have the circuit breaker kit(AR47675) installed(see photo below)? If CB kit isn't installed then 24 volt system is more subject to catch fire from bad wiring insulation.


 

[JDEM]

One common problem on these awful systems designed by AC Delco is the starter-motor loses its isolation and provides a path to chassis-ground. Sometimes all it takes to fix is to take the starter apart and blow all the brush-dust out of it. I never understood why Deere did not use the 24 volt system like used in the 1010s instead.
 

[bstover7@hotmail.com]

Bob,

I've rewired the batteries as per the black and white diagram posted. I've obtained all the correct voltages in the proper locations.
The generator light is on, even with the ignition off, and the lights are not working. The generator light goes out when I disconnect the 12volt negative terminal to the starter body. I'm thinking the short is in this circuit?
I'm going to clean the starter post, just trying to figure out how to get the 3rd bolt out of the starter.

Bruce