John Deere tractor burning up throttle cable

[Chocaholic]

Why not disconnect both ground cables at both ends, clean contact points with a wire brush, add a bit of dielectric goo and bolt them back up? Seems like a logical first step.

[LEAKYSEALS951]

I've got a 2009 x700 series. Never had that happen-yet.

1. Did the cables melt at the same points? I'd backtrace to see what the melted points lineup with.

2. That console area takes a lot of heat from the radiator and such, and also clogs up with crap.

I take a leaf blower and blast the whole area out, radiator and all every once and a while. During mowing season I will leaf blow the entire tractor down to keep the dried grass from building up in nooks and crannies. Hitting the radiator in reverse sometimes blast some serious stuff. Amazing what crap comes out.

I know mine is getting clogged though by the temp gauge creeping up as cooling begins to fail. Not saying it's the problem, but something easy enough to check.

[Baz]

Originally Posted by rfuerst911sc

-snip- The cable from the factory is routed from the console , past the radiator and then along the air filter inlet tube ending at the diesel throttle linkage.
So it really doesn't travel anywhere that gets hot . -snip-

I would check that radiator and see if it does indeed get hot where the throttle cable goes by it, Rick.....good luck!

[rfuerst911sc]

The areas/sections of the melted cable are not where it touches the radiator . It's further downstream with no apparent pattern . Downstream means zip tied to the plastic intake tube to the air filter or just hanging out in the air .

And I use compressed air to clean out the radiator pre-screen after every mowing . Yes the radiator gets hot but no overheating condition even when mowing in 95 degrees . This throttle cable is 3 ' long but only 2 inches of it touch the radiator . I hope to start work on the tractor tomorrow .

[cassisrot]

You might drop by your local JD store and ask the guys in the shop. They are knowledgeable and most times glad to help.

[LEAKYSEALS951]

I checked my JD cable today- It's metal wire surrounded by metal sheath. No real plastic to speak of. You aren't kidding, it really doesn't run in a high heat area.
It would be warmer as it goes towards the manifolds, but not near the radiator at all.
Good luck.

[rfuerst911sc]

So this morning I disassembled the ground wires . Cleaned up all dirt and lightly sanded the ends . The engine mount bolt was quite corroded . Other than that didn't find a smoking gun . Reassembled with dielectric grease on every cable end .

Removed fried throttle cable and installed new . Throttle lever moves nice and smooth . I had the hood and side panels removed and before putting them back on I figured I would try it out . Turned the key and heard a fuse pop 😩 .

The tractor has a 4 fuse panel . They are 15/15/30/15 Amp. The 30 Amp is what popped . And of course I am out of them so need to go get some . Ran my fingers over every wire bundle and felt nothing like damaged insulation .

I wiggled and pushed/pulled every connection and found nothing . Will get some fuses and see what happens . And I confirmed the throttle cable does not touch the radiator it is a good inch above it .

[rfuerst911sc]

Put a new fuse in and it popped as soon as I turned the key . I find it interesting that someone prior to me put a 30 Amp where a 15 should have been . Hmmmmm . So now I need to figure out what the short is . Not my strong suit but will dive in and see what I can find .

[Scott Douglas]

Does this tractor have an alternator on it?
Sounds like you've got a dead short in it if it does.

[rfuerst911sc]

Originally Posted by Scott Douglas

Does this tractor have an alternator on it?
Sounds like you've got a dead short in it if it does.

It does have an alternator . So to test that theory if I disconnect wiring at alternator , install new fuse and turn key on if the fuse doesn't pop then the alternator or the wiring to it are the problem ?

[LEAKYSEALS951]

You got me trying to hunt up JD wiring diagrams for my own issues.

If the alternator doesn't pan out. Just throwing out ideas- did the previous owner redneckify/ modify bypass the seat safety switch? It appears to be tied into ignition switch on low res diagram I found.

The seat safety switch was one of the first things I Delbert Grady "corrected" when I got mine-

[Scott Douglas]

Originally Posted by rfuerst911sc

It does have an alternator . So to test that theory if I disconnect wiring at alternator , install new fuse and turn key on if the fuse doesn't pop then the alternator or the wiring to it are the problem ?

That's how I would test it if doing it myself.

[rfuerst911sc]

Originally Posted by LEAKYSEALS951

You got me trying to hunt up JD wiring diagrams for my own issues.

If the alternator doesn't pan out. Just throwing out ideas- did the previous owner redneckify/ modify bypass the seat safety switch? It appears to be tied into ignition switch on low res diagram I found.

The seat safety switch was one of the first things I Delbert Grady "corrected" when I got mine-

I have not looked at seat safety switch but I do know it works . So I don't think it has been rigged . Thanks for the suggestion .

[rfuerst911sc]

Originally Posted by Scott Douglas

That's how I would test it if doing it myself.

I assume I would leave the battery positive cable attached to the starter but remove the switch/trigger wire/s ? Appreciate the help

[Scott Douglas]

I'd start by just isolating the alternator by removing the wires to it and taping them so they don't short out on something. Keep the variables to a minimum as far as the changes go so you know which one fixes it.

[unclebilly]

Disconnect the throttle cable at one end or the other. Then with a voltmeter, measure the voltage between the disconnected end and where it is supposed to connect with it:

Running

Ignition switched on

Ignition switched off

This will confirm your theory of a short up the cable.

You may just need a ground from the engine to the chassis where the throttle connects to send current that way instead of up the throttle cable.

[rfuerst911sc]

Originally Posted by unclebilly

Disconnect the throttle cable at one end or the other. Then with a voltmeter, measure the voltage between the disconnected end and where it is supposed to connect with it:

Running

Ignition switched on

Ignition switched off

This will confirm your theory of a short up the cable.

You may just need a ground from the engine to the chassis where the throttle connects to send current that way instead of up the throttle cable.

Unfortunately right now with the blowing fuse issue I can't perform key on or running measurements . Because as soon as I turn the key it pops the fuse .

[rfuerst911sc]

Suggestions from two JD forums suggested to look at seat safety switch for chafed wires . Also there is a wire harness that can chafe against the removable radiator screen . So along with the alternator suggestion I think I have a good starting point of things to check .

[rfuerst911sc]

The issue appears to be solved . Started inspecting wires today and found the seat safety switch wires were smashed/exposed down to bare copper . Looks like the factory/dealer/shop/previous owner routed the wire harness incorrectly . This tractor has a suspension seat so fair amount of movement . The way the wire harness was routed every time you got on or off the seat or hit a bump the wires were being pounded in between the metal seat bottom and the metal top of the suspension seat frame .

So I separated the wires and taped them individually . Then taped them as a pair . Then slipped into the factory plastic wire loom and taped the exterior of that . Then routed the harness the correct way and everything works . I mowed leaves for 30 minutes with headlights on . All works as it should including the seat safety switch . Pulled it into the garage and popped the hood open , throttle cable in perfect condition and cool to the touch .

I want to thank everyone that chimed in with suggestions . This is an amazing forum with some very sharp minds . Have a Merry Christmas and a Happy New Year !!!

[1990C4S]

Originally Posted by rfuerst911sc

This is an amazing forum with some very sharp minds, Have a Merry Christmas and a Happy New Year !!!

Technically, the JD forum diagnosed the specific cause...we just said 'current'....