JD 24volt charging

[MORRISONSTEEL]

Some wild tinkerer has removed the 24V generator which floats electrically isolated from the chassis and probably jammed on a 12V neg chassis alternator?
It maybe time to entertain a 12V conversion using the mighty Delco 44MT. It's a PM gear reduction starter that will wail an engine over like few starter can.
Lots of warm weather uses install a 4KW nipper but there is a 5Kw nipper that turns a 531 cu better .

That's what I say, convert it. But op does need to be careful that there is enough room for a gear reduction starter due to their taller nature. The fuel filter set up (depending on version op has) could also be in the way, but easily remedied. But I am not as familiar with potential room issues on the early 5020 as the 10's and early 20 series utilities. There is just to many aftermarket choices for decent $ out there to continue to diagnose an obviously tinkered with electrical system.

 

[buickanddeere]

The 44MT is an inline design unlike the Denso with the offset motor . The Delco 44MT may fit in places the less powerful 4 or 5 KW Denso won't.

 

[buickanddeere]

While this is a balky site to download. It does list some 12V starters in the 4 to 5 KW range that are either PM offset gear reduction and direct drive.

http://www.waiglobal.com/images/Pub...ernators and starters 05-2012 lo res blue.pdf

The mighty 44MT. To my knowledge the most powerful 12V starter on the market.The Delco 44MT Starter | Elreg

 

[Dave M7040]

What you need is called a Series parallel switch.
Large construction equipment and 18 wheelers from the 1970's used them all the time.
Here is a link showing how they are connected and where to buy.
You charge at 12 volts and start at 24
12/24 Volt DC 1500 amp Series Parallel Solenoid Relay.
Dave M7040

 

[Tx Jim]

What you need is called a Series parallel switch.
Large construction equipment and 18 wheelers from the 1970's used them all the time.
Here is a link showing how they are connected and where to buy.
You charge at 12 volts and start at 24
12/24 Volt DC 1500 amp Series Parallel Solenoid Relay.
Dave M7040

Before I installed a parallel switch on a JD 24 volt system I'd advise to just change it over to straight 12 volts and be done with it.

 

[buickanddeere]

Txjim has the correct answer.

 

[pmsmechanic]

I worked for a farmer in my younger days that had a 4010 with a series parallel switch in it. Most of the time it worked ok but when it didn't it was a pain.

A series parallel switch is about $120 -$150 on the internet and a rebuilt delco 12 volt starter is about $300. I would go with the starter.

 

[Tx Jim]

A JD technician I know installs new Iskra starters when he converts 24 volts to 12 volts. New Iskra starter cost about $325

 

[CraigM]

Wow, I've been too busy to check here for a few days. I didn't mean to start an argument. Thanks to all for the ideas and links to possible options to solve the problem. Between the I&T manual that I found, the parts guys at the local dealer and a lot of brain picking of the old timers around here, I have come to terms with the whole 24v thing. It's essentially the same as house wiring, where you get 110v between the hots and ground, and 220v between the hots. I've done enough wiring and working with electronics with bi-polar power supplies that I'm not too worried about putting it back on this tractor.

Provided the alternator works, I'm just going to keep the 24v setup. Why spend the money to fix what ain't broken? That leaves me with 2 questions:

The alternator has 2 terminals in the side to power the field and regulator. Does anyone know the polarity on them? If I can power that up, I can see if it's 12 or 24V, or working at all. The outputs are isolated from the frame as someone had said, and it apparently charged the batteries, so it may be 24V even though it's marked 12. Based on the serial No. of this tractor, it shouldn't even have a delco alternator. With all the hacking that was done on the electrics in this tractor, anything is possible.

TxJim, can you post a better picture of that fuse kit that was installed to prevent fires, or give me a part number that I can take to the dealer?

 

[Tx Jim]

The breakers that were field installed have no illustrations(photos ) in JD parts catalogs. Part number for breakers is AR47660. Can you post a photo or part numbers for the alternator on your tractor? Here's is the parts photo of the Motorola 24 volt alt that the very few 4020's with AC cabs came with from the factory. I found a photo with the mounting bracket for a 3020 which should be very similar to 4020 BUT bracket & breakers are mounted to starter incorrectly but will give you the idea.