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JD 5103 short in fuel solenoid circuit

Jeffrey Lambert I have a John Deere 5103 that keeps blowing fuses for the electronic fuel solenoid circuit. The wiring from the fuse panel to the solenoid is short and encased in plastic so it doesn't seem likely that the short is in the wire run. I disconnected the power wire to the solenoid, replaced the fuse, and turned on the power. The fuse did not blow. I put the power back on the solenoid and it popped the fuse immediately. Has anyone else had this problem with the 5100 series JD's? Is it likely that the fuel solenoid needs to be replaced or is there a pinch point in the wiring harness in one of those hard to see spots that is problematic with wearing off the insulation?
Dale G. Basgall Jeffrey : On that unit I believe on the thermostat housing there is a cold start switch, you will see a wire go to the fuel pump. I unplugged mine cause it also was shorting out the fuel solenoid circuit. I didn't need mine cause I am in Hawaii. Mine has run fine since I did that.

Dale G. Basgall

Larry Davenport Jeffrey,
I don't have the same problem as you. I have a 5203 John Deere and I don't have fire to the electric fuel shut off solenoid. I've changed my fuse, made sure all gears are where they are supposed to be, checked coolants and oil. I have fire everywhere but the electronic fuel shut off on the solenoid. I can run a bypass wire from the battery to the electronic fuel shut off switch and it will start and run fine. Any suggestions.


Clint McCaa I had the same problem. Disconnected the cold start and she ran smooth. As soon as I touched the wire to the cold start I blew the fuse. Aparently there is a short in the cold start element. I'll replace it later.
Rickey Doyle
locating solenoid

CLAYTON BLACKERT THANKS GUYS: I had the fuse blowing problem on my 5103 removed wire to the cold start solenoid and now starts fine I live in florida so wont replace the Coldstart Sol. Thanks for the information. Clayton
Terry I seem to have the same problem with 308 hours. Please someone tell detail on which wire etc to disconnect.
Terry Andrews Thanks for the help. I called the dealer and they said it would be over a week before they could look at it. I pulled one wire and then cut grass this afternoon. I do intend to get the cold start fixed since I am in Alabama and use the tractor to put out round hay bales weekly usually at night.
Re: JD 5103 short in fuel solenoid circuit

My 5205 was in use and I turned it off to unload my trailer. Would not start. Fuse F2 20 AMP was blown. Kept blowing. I saw this POST doing a search for Fuel Solenoid fuse blow! What a hit!
Disconnected the Cold Start Sensor/Switch @ thermostate housing and with new fuse runs like a champ.

What does this switch do? I live on the Gulf Coast in Louisiana and it does not get cold very often. It is not Hawaii, but close.

Thanks for this post and I added a picture because it might help out someone else.


ed Had the same problem with my 5103. I disconnected the cold start sensor and put in a new fuse and engine started fine. Wish I had seen your post 3 days ago. Thanks


Ed Jack

After I replaced the switch shown in your picture I told a mechanic about you leaving it unpluged and that it was for cold starting. He said that it is a temperature sensor which will go out if the engine is about to overheat. He said he would not dare run his tractor without it for fear of ruining his diesel. Thought I would pass this on.


Gary Shirey Yes, unplugging the "cold start" switch fixed the problem on my 5103 today. I also tested the switch with my test meter and found a full short circuit internally. I believe it should be OPEN or have some resistance value, if it's in good condition and at ambient temperature. After confirming the short, I put in a new fuse and started the tractor. It ran fine and restarted fine after warming up. Now, I still don't know why the "cold start" switch failed. I will investigate, since I believe in restoring protective devices to full functionality. I also think JD should rename this thing as a "high temperature cut-out" or "over-heat switch". It's function is to protect against prolonged operation at excessive coolant temperature. I also, check the coolant and it was fine. I will update if I learn more about this thing. I'm in north Louisisna.
Bill McLain HELP! I am trying to help a friend so that she does not have to pay a fortune to JD to fix this problem. I have all the symptoms, I have it to a point where the fuse no longer blows, but when I try to crank it won't do anything. It clicks, but then nothing. I have verified the battery is not in any way contributing to the problem. Everyone keeps talking about disconnecting the cold start sensor but as a total amateur I cannot seem to figure out where that is located. This is a JD 5203. If someone could explain in detail how to locate this and disconnect it I would be very very grateful. Thanks.
bill jones My problem is I don't have any power to the fuel cut valve and none of the fuses are blown. Does someone have a wiring diagram so I can see where the power comes from
bill jones My problem is I don't have any power to the fuel cut off valve and none of the fuses are blown. Does someone have a wiring diagram so I can see where the power comes from
bill jones My problem is I don't have any power to the fuel cut off valve and none of the fuses are blown. Does someone have a wiring diagram so I can see where the power comes from
Mark Gray I had a problem with a bad cold start switch this past winter. I replaced the switch and the 20A fuse and all was well, that is until the day before yesterday when I had made a couple laps around the field while bushhogging and turned off the tractor to do some fence work and the tractor would not restart. It turns over but will not start. I checked the fuse and it looked okay. Does anyone have any ideas of what the problem might be this time?
Oh, it is a JD 5103.

shane thanks many times over, spot on

Doug Anderson Had a similar problem with my 2008 5203. Tractor shut down as I was entering the goat field. Turning the key had no result. Found a blown 10A fuse which the box had labelled as "Satart Relay 10A" but the operators manual shows as a "20A Spare". Replaced the fuse with a 20A, blew it as soon as I turned the key. Couldn't figure out what it was for. Found this thread and disconnected the sensor at the thermostat housing, replaced the fuse with a 15A to complete the circuit and am back in business. Believe the comment about this being an overheating sensor and will look into its function later - today is Sunday so can't check with the dealer. Thanks to all above for their input.
Doug By the way, the tractor had been running for only a few minutes and was no way near to an overheating state. Never had any issue like this before, even when mowing 25 acres of hay with a haybine in 32 degree celsius summer heat. Evidently a bad sensor (tractor has only 640 hours).

Scott Kirkland where is the fuel cutoff solenoid fuse located?

D Benson 2008 5203 working fine on a 70 degree day,stopped to load trailer and nothing from crank, no click, nothing.

read the forums a bit then checked the tractor. Battery good-Solenoid good-Starter good but no power to small positive side of solenoid so I checked the ignition and it showed good. I traced back the wire from the solenoid to a starter relay behind dash. The relay had 12.8 volts on one side with the solenoid open. Nothing on opposite side with key off, acc, or start. This is the side going to main solenoid at starter. Found there was no power going to the small starter relay behind dash during any of the ignition cycles.

So I thought I would check the cold start sensor but didn't expect to find anything because all fuses were good. Until I read that Doug in the prior post had his 5203 blow a fuse in the spare fuse slot. Well mine was blown as well. Unhooked the cold start and fuse didn't blow so that was an issue. but still no power to starter solenoid so I rain a hot wire from the start side of the ignition directly to main solenoid and it started like always.

Anyone have any idea what is stoping power between ignition and start solenoid? Im guessing a broken wire but didn't want to undo thew complete wiring harness yo see. Gonna order a new ignition to see it there is another lead on the back that might power the small start solenoid in dash.

Any ideas

Rob Thanks guys very much . My 5103 would not start . Checked the fuse . Sure enough it was blown . Unplugged the cold start switch . Put in a new fuse . It cranked right up and ran perfectly .
Brian Cox The cold start switch and associated circuit is supposed to advance fuel timing when it is cold. It is not a protective device for when the engine gets too hot; it just turns off the advance once the engine warms up. You can get manuals if you Google "john Deere 5103 manual" at a john deere site or others. Enjoy!
Re: JD 5103 short in fuel solenoid circuit

Just a conformation of what was said. My 5103, same problem with cold crank switch. Unplugged it and replaced F2 fuse and bang, back in business. Thanks guys for your input.

sean I have a jd 5205 that iam working on now. This as well has blown the switch fuse. I replace and again blown. Now researched found that the cold start advance thermistor might be the issue. Well here in lyes the problem this one doesnt have the sensor in the thermostat housing. I disconnected the wire on the injection pump and still blows fuses. I had it running when I first replaced the fuse but had to shut it down due to requiring to put panels back on. Also cleaned the fuel filter primer as it was leaking like a sive. Then NOTHING!!! Could this have something to do with the fuel leaking in or on the starter? I am not quite sure what the issue is. HELP PLEASE.
TIMON 56 doug anderson , thanks for your info on the spare fuse. Unplug thermostat sensor replace your spare fuse, (because its not) our tractor fired right up. Due to a mislabel in the manual, would of taken this tractor in on monday after many days of trying to figure it out! SO SHAME ON YOU JOHN DEERE FOR MISLABELING YOUR FUSES OR MAKING A TYPO!!!! THANK YOU DOUG .
sparkie let me know if u get this
sparkie doodle check fuel solenoid circuit disconnect cold start switch wire at thermostat sensor check for good fuse

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