John deere 4020 batteries

I have a few questions about my john
deere 4020 1964 tractor it's 24 volt
, I bought it last year she always
started great then over the winter it
just could not keep it's charge on the
batteries so I bought 2 new ones
thinking the old ones just were bad
now I have to charge it before every
start , how do I keep it charged ?

You must have a current draw somewhere. If you can afford to I?d change it to a 12 volt system my 3020 was that way when I bought it and I later converted my 4020 to 12 as well

If your tractor is set up as it left the factory, and you have a battery discharge issue, typically the RH battery will get " drained" by the generator or starter having conductive brush dust/debris/moisture in it.

A few of us crusty old DEERE GURUS understand and appreciate the General Motors/DEERE 24 Volt system that was used, for the rest of you it can be a $$$ heartache unless you take the time to read up on it and understand it or have a knowledgeable "tractor buddy" to help.

To summarize:

1. A 24 Volt 4020 diesel is probably NOT the best choice for a tractor novice.

2. It's a darned good system when maintained properly, but a nightmare if not and exposed to a "wrench" that doesn't understand it.

3. Many have been converted to a 12 Volt system (and I can forward a diagram as to how to do that, if you'd like) but the danged OEM 24 Volt system sure does crank the snot out of the engine when in good condition.

Ditto what the others stated. If your tractor is to be used not a "collector type" I also recommend to change it over to 12 volt system.

Many times I just unhook one of the right hand battery cables when I get done using it , not the most convenient thing but saves the battery.

I have seven different 3020-4020's that were all originally 24 volt systems. I use them each untill they caused problems then changed them over to 12 volt. Yes the 24 volt spins them faster but mine all start fine with heavy cables, good batteries and good starter. I have also changed over 20 others with no regrets. With age the 24 volt system always needs something done done to it. Tom

I agree with the others. Convert to 12 volt. use a one wire alt. Doing so may/will require a complete 'rewire',but worth the effort. I do my old farmalls that way. Use em till the old 6V system causes issues. Strip out the system and completely rewirebuild your own new harness. Use a one wire alt.(about 55bucks). no more issues,EVER.You can use two 6v batterys in series;two 12v in parelell;or one 12 volt. However,one 12 may not have enough 'poop' in cold/cooler weather

Why not install some variation of this.


https://www.ebay.com/itm/Auto-Battery-Disconnect-Kill-Cut-Off-Cutoff-Switch-Solid-Brass-2-Removable-Keys-/321065414703

I put a 3 wire Delco on mine and you can get a starter for a couple hundred bucks . You can also buy a kit to convert it but they are around 700$ You could also fix it the way it is and keep the 24 volt system

I recently converted FIL 4010 from 24 to 12 volt. Not a real difficult process.

I considered many of the conversion kits to be over priced, and they all seem to come with a one wire alternator which loses function of the charge lamp which it already had.

I ordered a 12 volt planetary drive starter (under $200.00). I had a spare Delco 3 wire alternator, and a salvage start solenoid from an old Ford pickup.

I used the existing generator bracket, turned it over and used a cut off blade on an angle grinder to notch one end of the bracket to give clearance for alternator. Added a large washer between alternator pulley and fan to extend pulley for better belt alignment. Used existing belt.

Using a one wire alternator in this application you will lose the function of the charge light. I prefer a 3 wire alternator. Loop #2 pin to output. Black wire at center G terminal on old 24V regulator is for lamp, connect this wire to #1 on the alternator. On the main start switch I moved the other end of light wire from GEN on the switch to Lights A on the switch. This bypassed an internal resistor in the switch and connected lamp to 12 volt source.

Existing Blue and Brown charge wires were in good condition so I kept them. As per other?s advice I added an auxiliary start solenoid between start switch and starter solenoid.

Tractor is not used during winter so I am using one group 31 1000 CCA battery.

I am very happy with the change over. Tractor starts as good as before and alternator begins charging immediately. This setup will be much simpler to maintain, and new starter and alternator would be far less costly than old generator/regulator or starter replacement.

Spider-Man, I'm pretty much in Bobs camp on this one. When I farmed with those 24 volt tractors and was a used tractor dealer I more then once (like other gents here) discovered a starter motor all filled with copper brush particles caused a battery discharge. Where the two batteries series tie in the middle there's a jumper connected to frame/ground whereby one battery is effectively POS grounded and the other NEG grounded (that's how they were designed and built as John Deere Service Bulletins and wiring diagrams indicate which I found to be correct) and excessive copper dust in the starter motor can provide a fault current path to frame/ground thereby draining the battery. You may be able to remove the starter motor and clean it which (if that's indeed the cause of your battery drain) might possibly cure it??? Is it BOTH or just one battery that's discharging??? There could be a ton of other causes mind you, but for now based on such limited information and not being there this is ONLY one possibility.

Like Bob well noted that system is NOT for rookies or anyone electrically challenged. I (an Electrical Engineer) owned and maintained them with no problem, but many farmer Billy Bobs are out to lunch and for them a 12 volt conversion (like the other gents posted) may be the better option.

Best wishes

John T

What do you mean RH, looking in which direction? Thanks

It's both batteries I tried starting it this morning end had no luck , I'll have to try and clean the starter

(quoted from post at 17:10:33 06/11/18) What do you mean RH, looking in which direction? Thanks

Click to expand...

By convention, RH as you would sit in the seat or stand behind it.

Sitting

(quoted from post at 02:24:47 06/12/18) Sitting

Click to expand...

Yes sitting in seat. I was taught many yrs back when I began employment selling parts at a JD dealership that when referring to a side of tractor/equipment to consider myself standing behind or sitting in seat of that equipment