Help! 24 Volt system

[Magoo1]

I know I'm on the crawler site, but you fellows have a lot of talent. A 1965 model 3020 with the 24 volt generator system. Some one has installed what looks like a Delco SI10 alt. but has a tag "24Volt". The Alt. does not have a seperate "ground" terminal and from what I have read so far is ( Neg ) ground to the frame?

I think I could make the system a Neg ground 24 Volt system so the charging and starting system would work but don't want to fry everthing else.

Please share your thoughts or wiring diagrams.

Thanks, Magoo

[Jimmy in NC]

Magoo-

I don't know if any of the crawlers used 24V but know that there have been some posts on http://www.johnnypopper.com/forums/ . You may try searching that message board or posting on there.. I know John T and some of them over there are real good on electrical problems and have a bunch of experience with integrating and such.

Jimmy in NC

[JD440ICD2006]

Magoo, To my knowledge, 24 volt systems did not show up at JD until the 1958 720 Diesel tractors built in Waterloo. This system actually had two separate circuits. It used two 12 volt batteries, charged at 24 volts, but the lights and other 12 volt stuff ran off of a split circuit.
The 24 volts to the starter and from the generator used the frame as the one side of the circuit, and wire for the other side. It had a split in between the batteries for 12 volts.
One of the problems was having too much load on one battery for the 12 volt circuit.
Here is site where you can ask if anyone has one of knows the answers to your questions on the JD 3020.
http://www.greencollectors.com/mnps/boa ... &startat=1

[Lavoy]

I don't think the alternator is grounded as such. Everything else on the tractor is 12 volt, the only thing that runs on 24 volts is the starter. There is a system ground from one of the batteries to ground underneath the platform, that is how the 12 volt part gets grounded.
The best way to fix them is to just do the 12 volt conversion, and then you are done with it forever. I don't have them on hand, but short time to get them. I do have a 24 volt generator for that tractor on hand if need be.
Lavoy

[CatD8RII]

Im not 100% sure on this but judging by the vintage of the 3020, if its a 24V start system, should use a series parallel switch. In theory they "switch" the batteries in sereies to 24V to start then in parallel to 12V to run and receive charge. Lavoy has the right idea with the straight 12V conversion as these dual systems (from my dealings with them) have been problematic to say the least. The only other way to switch 12/24 that Im aware of is a Duvac which is an electronic alternator control.

[digitup]

I had an early 850 dozer that was that way 24 start up and 12 run the series parallel switch was always a problem .I was lucky enough to change this switch a wire harness and the starter assembly over to completely 12 volt.I am still wondering why they bothered with the 24 volt system that 6-414t started nice even when it was real cold . 24v is a pain to work on a b#$%! to fix and no two repair men have the same theories on fixing the stuff .Try to find what all has been changed and change it back to good old 12 volt.I have both 12 volt and 24 volt on the drainage plows and the old one is getting to be a pain seems no one can figure out these darned things .Every so often I have to go and figure the problem It is usually the change over switch and it is never fun.The new ones are two separate systems now that is easy enough .Digitup.

[Stan Disbrow]

Hi,

I used to do the opposite - change the charging part of the system over to 24 volts and run the batts in series all the time. I tapped off only the ground-side 12v batt for the accessories (lights and such).

This also worked like a charm. It was ther silly series-parallel switch that was the problem child. Why in heck Deere didn't use a full 24v system with 12v tap-off in the first place escapes me.

I guess in the end we have a choice to make - change the 24v starter for a 12v one and go parallel-only, or change the generator/regulator for a 24v one and go series-only.

Later!

Stan