My dear old dad's JD 4300 has some issues

[keckerjr]

Tom here with some ongoing electrical & starting issues with my dad's John Deere 4300 Compact Tractor (Sync Reverser model).

The story started by the tractor refusing to start: went from a flawless, dependable unit to one now sitting under a leanto shed (at least it's out of the weather).
Dad asked for my help, so I wasn't going to pass up a chance on working on his big 'Green Machine'.

To date I have checked all of the following (all with satisfactory results):

a) battery (12.7 volts and 590 cca in load test)
b) starter (bench tested. Switch kicks in and motor purrs when it should)
c) ignition switch (ran continuity check, but I bought a brand new one in case...)
d) all fuses
e) kill switches (I found 3 including the one under the seat)
f) wires (none appear to be loose or frayed)
g) condition of battery cables (engine ground and post on starter motor)
h) although I don't know of a procedure to check relays, I put a brand new one in the ignition port
i) cleaned all accessible electrical terminals and contacts are bright.

So what doesn't work ?

1. Well the hazard lights nor headlights don't work at all (with ignition switch in place or removed). I hear a blinking sound coming from behind the steering wheel compartment, but the lights don't flash.
2. The tractor will not start: it will not turn over. There is no power at terminal leading to the starter switch when ignition switch is keyed to start.

I have read threads from others experiencing similar problems with their 4300, but with the lights refusing to come on DESPITE power going to the fuse block, I'm stumped.

Before I put the starter back on (what a bear getting to the hidden 17mm bolt: thanks JD), I hope someone out there will express their views.
A private e-mail response is also ok with me, but I figure the value of a forum such as this is the information exchange.

I have a Technical Manual CD on order for Tuesday.

Thanks !
Tom

 

[robertgalka]

I remember my 4210 lost all power, and there was a bad connection right by the starter motor. From what I remember it was about four inches from the starter motor, and the wire was about 1/8 in diameter.

 

[beenthere]

Hopefully you have browsed several threads on this TBN forum that have dealt with the 4300. And good that you now have the tech manual on CD coming.
Not so good that you tore into it as now we have not only the original problem, but the risk of various things (sorry, not meant to demean ) you have done.

But, with the tech manual, you will have a lot of trouble shooting that you can do as well as the circuit diagrams to follow. Don't give up hope.

I'm interested, as I have a 4300 and it has been a very dependable tractor for 15 years now.

Maybe the mods will move this out of the "lawn and garden tractors" and into the "owning and operating" where it may get more exposure to others with this size tractor.

 

[boggen]

when ya turn the key, due you hear a "click" or like coming from the solenoid on the starter motor?

 

[RoyJackson]

The original problem sounded like the thermistor went bad, but now it's hard to pin down any particular issue. The thermistor going bad would prevent starting, but the lights should come on.
It's no telling what wiring may have been damaged or disturbed during the disassembly you've described.
At this point, I suggest focusing on the thermistor (it's behind the fuse panel) and replacing it. Then reassemble everything and see what happens. As you reassemble everything, look closely for wiring problems (for the lights) and bad grounds.

 

[Egon]

There may be more than three kill switches depending on how it's equipped.

Try giving the battery a very complete charge and then try.

Note: my JD4200 has intermitent starting issues. Slapping the cowl helps at times.

 

[patchnball]

thermistor...replace......hard to believe such a small item has such a big effect......

 

[dfkrug]

h) although I don't know of a procedure to check relays, I put a brand new one in the ignition port
i) cleaned all accessible electrical terminals and contacts are bright.

Well, Tom, the #1 culprit for most electrical problems is the battery/batt terminals/connections.
Barring that, since you say the headlights don't work, that points to the starter switch.

After verifying that none of the interlock switches are causing a problem (a big source of
problems), check the relays that they control. You mention checking one in h) above. Here
is where the electrical diagram is needed. You can swap them around to check for a
non-op unit.

 

[jenkinsph]

Did you make sure the pto switch is off?

 

[RoyJackson]

As an FYI, most of the issues you guys have suggested would prevent the starter from turning, but would not prevent the lights or flashers from coming on.