Help John Deere 3020 24v Starter Replacement Wiring

[TheRobertRalph]

I finally broke down and bought a new starter. This is an aftermarket and I need a bit of help to get it wired up since it is just a little different than the JD stock one.

I have enclosed pictures of the current one and a referece to the old one.

24v System. There are two big wires coming from batteries. The negative goes to the top post on the solenoid.

1) The + cable went to the side of the old starter on a lug. Then another lug came out of the starter with a bent piece of metal connecting it to the bottom lug of the solenoid. Can I just hook the + to the bottom lug of the new solenoid? My instict is that I cannot. Also, it has a bent piece of metal going from that bottom lug on the solenoid to the side but there is no lug on the side to mount the + cable to.

2) I'm curious to understand the smaller lugs (1/4"?). There is one labeled "S" and I believe that is the starting switch? What is the other one for? There was a grey wire going from it to the + lug on the side of starter before.

Old Starter wiring:

New:

This post was edited by TheRobertRalph on 06/12/2022 at 06:14 am.

 

[wore out]

The new starter is made for a 24 Volt system with one ''side'' of the 24 Volts grounded to the chassis.

The 3020's 24 Volt system is grounded to the chassis at the ''midpoint'' and uses an "isolated ground'' starter and charging system, the two are incompatible.

While you COULD change the type of ground at the tractor the fuel gauge, oil and generator ''idiot lights'', and all work, road, and any warning flasher lights would have to be changed to 24 Volts.

Best to return the starter and get the correct ''isolated ground'' style or get a 12 Volt starter and $60 generic 12 Volt alternator. At that point, you can swap around some wires and keep the two 12 Volt batteries, the 12 Volt lights and ''idiot lights'' can be retained. The fuel gauge is already 12 Volts, but is most accurate on (+) ground, if good accuracy is important that may need to be changed at some point.

This post was edited by wore out on 06/12/2022 at 08:13 am.

 

[Tx Jim]

I agree with what wore out stated. Get correct type of 24 volt starter or change to 12 volt system. If tractor was under my supervision I change it to a 12 volt system

 

[John T]

I agree with the other fine gents. Originally the tractor used an ISOLATED GROUND 24 Volt starter, it as
well as the Generator are two terminal 24 volt HAVING NO CONNECTION TO FRAME GROUND. You should be able to
purchase the correct 24 volt isolated ground starter but they are pricey.........

John T

 

[TheRobertRalph]

(quoted from post at 17:17:13 06/12/22) I agree with the other fine gents. Originally the tractor used an ISOLATED GROUND 24 Volt starter, it as
well as the Generator are two terminal 24 volt HAVING NO CONNECTION TO FRAME GROUND. You should be able to
purchase the correct 24 volt isolated ground starter but they are pricey.........

John T

Thank you all! I have ordered a 12f conversion kit. I am just going to go that route.

You were a great help!