Starter question for John T and others

I have a J D 2550 with a bad starter. It has 2 small
posts on either side of the solenoid. The new starter
has only 1 small post. Do I hook both small wires to
the 1 post or did I get the wrong starter? Thanks in
advance.

Wrong solenoid. One small wire is the start wire and the other is the ballast resister by pass. So hook both small wires up could cause some odd problems

Why use a ballast bypass on a diesel ? Don't connect anything to the bypass and she will be grand .
More importantly the tractor needs a ground cable direct from the battery to one of the bolts that clamps the starter down.
A lot of voltage and cranking power is being lost as the current travels through the sheet metal with the factory ground system. Gets worse with age .

Your old starter has 2 posts? Were both connected to a wire? A single small post would normally be correct for a diesel as it has not ignition resistor to bypass.

One of the 2 posts is for the wire from the switch start terminal. If your old one only had one wire connected, put that wire on the single post of the new one.

Ah but he does not say gas or diesel so which is it no way to know by his post

Hey, guys, I’m an idiot. Went and looked at the starter. Nothing connected to second post so new starter good to go.

JD 2550 models were all diesels.

Ben

Well again lack of info not all people know that but know howto trouble shoot starter problem if they have all the info needed

doc, I don't have a wiring diagram so can only offer some information that might help.


1) A solenoid that has TWO small terminals could possibly be used:

a) One is the + voltage input activation to the solenoids coil while the other serves as the - ground return. Those solenoids apply a Hot and a Ground to the coil to close the contacts to engage the starter THEY DO NOT USE THE FRAME AS GROUND, that's why they need two wires + and - Those are not typical but hey IM ONLY SAYING that method can work.......

b) One is the + voltage input (S) and the other is hot ONLY when its cranking (I) but those were typically use on a GAS tractor so the
(I) served as an ignition ballast by pass. NOTE such a solenoid COULD STILL BE USED AND WORK even on a diesel that does not need the
Ignition (I) ballast by pass terminal so long as voltage on S activates the coil and it uses frame ground return. BUT IN THAT CASE
(like if was wrong solenoid) you would ONLY need the wire thats hot in switches start position and not use the other...


2) A solenoid that has ONLY ONE SMALL TERMINAL

With ONLY one terminal the activation coil is between that small terminal and frame ground. When hot voltage is one one end of the coil and its other end is to ground. the contacts close and the motor cranks.


Sooooooooooo

A) Use a volt meter or test lamp and see which of those two wires becomes hot (with respect to frame ground) with the switch in the START position ?????

B) If that wire connected to the solenoids single terminal activates the solenoid (must mean the solenoid uses frame as ground return)
USE IT AND DISREGARD THE OTHER WIRE

C) I do not envision hooking BOTH wires together or needing BOTH but I have no diagram, so no warranty and I defer to someone that has a diagram ....

You simply have to see which wire does what ????????????? If one becomes HOT with switch in the start position and iffffffffffff the new solenoid uses frame ground return (must be with ONLY one terminal) and iffffffffffffffff the solenoid closes using ONLY that wire USED IT NOT THE OTHER.

DOES THAT HELP ?????????????

PS may some other gents have a wiring diagram and can answer your question, but if not the above may still help you understand what you have and how to wire it

Post back what you find and any other questions

John T

PS If someone has a diagram that shows that other wire is needed THEN YOU MUST HAVE THE WRONG SOLENOID. My post below is still informative but if that other wire serves a purpose by all means get the correct solenoid/starter !!!!!!!!!!!!!!

John T

(quoted from post at 21:09:13 08/24/20) Ah but he does not say gas or diesel so which is it no way to know by his post

Click to expand...

Never seen a gas 2550 .