4020 24v questions (pt 2)

[cfk]

Hey guys-

I asked a few questions about the 24v system a while ago and learned a few things, but I have come up with a few more questions and hopefully you can help.

It was suggested I put a battery disconnect on, which would help with battery life:
1) Does this help only if there is a drain somewhere, or is it just good for the batteries in general?

2) I've read/heard different information on this, but where does the disconnect go? Between the two batteries? And the ground wire needs to be isolated as well? If the disconnect is off to one side or the other (between the starter and either one of the batteries), I assume there is still a completed circuit with one of the batteries because of that little positive ground wire?

I replaced the left battery a couple years ago, then replaced the right battery this past spring, now the left battery is junk (also only a few years old) and I'm replacing it now - is it giving me problems because I didn't replace them both at the same time? My neighbor has a 24v 4020 that hasn't given him issues at all - he'll leave it sitting for months at a time and it will start right up no problem.

3) If I want to put a battery maintainer on it (over the winter or long periods of inactivity), if I use a 24v charger/maintainer, can I put the negative clamp on the LH negative post and the positive on the RH positive post and maintain both batteries at the same time? Are there any specific don'ts when charging/maintaining/jumping?

4) If I converted the tractor to a 12v system, does it still use 2 batteries? If so, what makes the 12v system better/more reliable?

Thank you in advance!

 

[SamV]

My 4020 was already converted to 12V when I got it and it still has 2 batteries. Really easy to work on with that setup. I also have a new wiring harness so all is good.

Sam

 

[Tx Jim]

When converting 24 v to 12 v whether one needs 2 12 volt batteries vs one 12 volt battery is determined by Winter temperature in your area. One high CCA 12 volt battery in combination with a .gear drive starter will start most diesel engine in warmer climates.

Requirement of a battery disconnect switch is just one personal opinion. Adding battery disconnect switch would lessen chance of an electrical fire more especially on a 24 volt system.

12 volt system is better because most ordinary tractor owners & some repair technicians do not understand how JD 24 volt electrical system was designed to operate. Most don't understand that the JD 24 volt starter, generator & voltage regulator have no ground connection to tractor frame.

Yes a 24 volt battery maintainer or 24 volt charger can be attached to LH front battery negative post & RH front battery positive post.

 

[Duner Wi]

TxJim said and i believe it to be absolute truth.

12 volt system is better because most ordinary tractor owners & some repair technicians do not understand how JD 24 volt electrical system was designed to operate.

 

[JD Dave]

If your 24 volt system is working there's no need to switch to 12 volt. Armed with a tech manual with the schematic and a top notch automotive electrical shop you should be fine. You can also charge the two batteries independently at 12 volts.

 

[Fixingfarmer]

I think you have identified one of the issues that I was always concerned about master switch wise on my 3010 was that I think it would take 2 probably on the positive side. Just to be able to reach them and that’s not the normal way it’s done…

The 24 volt is ok if you develop an understanding of it but can be a mess if someone has modified it let’s say the starter has a draw and you really should tear into that but there’s some creative wiring that’s gone on around the 12v ground. How much do you want to replace before giving up? do you want it totally original or do you want it to be simpler and more functional do you want the generator or do you want an alternator?

You have options if you convert. Like tx Jim said one 12 volt (I’d pick 950-1000 cca cheap truck battery) if it’s not hooked to the snow blower.

I have a 4020 that has 2 6volts in a homemade battery box that fits 2 in it nice and tight. 600cca a piece. You then put a cable from negative to positive between the batteries to get the 12v. (I believe these were 4440 batteries I’m unsure of group size)

If you use the original battery box(s) your options I think are the skinny 12 like a gas tractor would have or like what you have now to get 24 you just run them in parallel so there’s an extra cable. Negative to negative positive to positive.

Ground becomes simpler as the chassis 12 volt ground is now the ground for everything. I’ve used the mount for the single point actually and put a real cable on where the wire and fuse were since it’s a 3/8 bolt.

Jumping is simpler if converted if 24v it shares all of the struggles of a 24 volt machine when it’s time to jump you get to separate the batteries before hooking the cables and charge each battery individually

It’s not much different than the 4440 really with the 6 volt batteries one on each side that would be your other option if you wanted to wire it similar to how it was I guess one six volt each side and you wouldn’t need the ground.

Confused yet? I’d convert it and be done (alternator yes please) just pick what batteries you prefer. I don’t like them skinny ones.

Also unfortunately this idea hasn’t died out entirely at the factories Fendt still does it. There’s a simpler electronic transfer switch incidentally that’s part of their master switch. Gee, I wonder why it’s there? Big warning labels about jumping the tractor.

 

[miangus]

I use two inexpensive 12-volt battery maintainers on my 64 3020 with the 24-volt system. Just connect them to each battery separately, works great. Disconnecting the battery that is connected directly to the starter does seem to help, I have been told that debris inside the starter end cap can cause that battery to have a slight continuous draw. I pulled the starter end cap and cleaned that area, and it seemed to help.

 

[Tx Jim]

TxJim said and i believe it to be absolute truth.

12 volt system is better because most ordinary tractor owners & some repair technicians do not understand how JD 24 volt electrical system was designed to operate.

I've forgot the number of times I've read on WWW that JD 24 volt system is positive or negative ground system when in reality the starter, generator & voltage regulator have no ground connections to tractor frame. Yes JD 24 V system lights & electrical accessories are split & have either positive or negative grounds.