Kubota L3400 electrical problem

JGARD · May 2, 2016

I've had a Kubota L3400 for 10 years and its been a great tractor! But has recently begun to shut off after starting. When it shuts off I hear a clicking sound. If I turn the key off and on and I hear a solenoid click it will start but then usually shutdown again in a few minutes, sometimes quicker. If I turn the key from off to on position and don't hear a click it will not start. I wait a few minutes and try again and then I hear the click and the tractor will start but usually shuts down again. If I keep this up while trouble shooting it will eventually keep running and I have to wait until the next day to see the problem again. Any ideas? I put a voltmeter from positive side of fuel solenoid to chassis and I get 12v until the tractor shuts off. I can't find a diagram online and am not sure what else can cause this as the safety switches seem to be working. Very frustrating, this is my first post on this site please be kind and thanks for any help or ideas.

TBN Support · May 2, 2016

Welcome to the forum! :welcome:

I'm going to move your thread on over to our Kubota section to see if we can find you some advice.

ritschner · May 2, 2016

If you have no voltage at the fuel solenoid with the key on then it is not the fuel solenoid. Possible causes are seat switch, intermittent ignition switch, or even a partially broken or corroded fuse. The seat switch will normally only cause problems when trying to run the PTO or trying to move the tractor. The cheapest and easiest thing to try is to replace the two fuses that control power to the fuel solenoid. They will sometimes fracture due to vibration and can cause the problems you describe. Both are labeled Key Stop with one fuse located in the box on the left side above the clutch pedal. It is the lower 5 amp fuse on the left side of the twin vertical rows. There should be a spare already in the lower portion of the box. The other is in the outer two fuse box to the left of the battery. It should be in the rear of the outer box and is a 30 amp J-case deep fuse. If nothing else you will have a spare fuse, so start there. The other possibility is an intermittent ignition switch

JGARD · May 3, 2016

ritschner said:
If you have no voltage at the fuel solenoid with the key on then it is not the fuel solenoid. Possible causes are seat switch, intermittent ignition switch, or even a partially broken or corroded fuse. The seat switch will normally only cause problems when trying to run the PTO or trying to move the tractor. The cheapest and easiest thing to try is to replace the two fuses that control power to the fuel solenoid. They will sometimes fracture due to vibration and can cause the problems you describe. Both are labeled Key Stop with one fuse located in the box on the left side above the clutch pedal. It is the lower 5 amp fuse on the left side of the twin vertical rows. There should be a spare already in the lower portion of the box. The other is in the outer two fuse box to the left of the battery. It should be in the rear of the outer box and is a 30 amp J-case deep fuse. If nothing else you will have a spare fuse, so start there. The other possibility is an intermittent ignition switch

Thank you very much I will check all per your recommendations.

JGARD · May 9, 2016

I checked the seat switch, ignition switch, and fuses and these all check good. The tractor never shuts down once the engine warms up. Is there anything on the engine that can cause the tractor to shutdown? When the tractor shuts down I do not have voltage on the fuel relay coil. I can not find an electrical drawing for a Kubota L3400. Any thoughts are very much appreciated.

teg · May 9, 2016

Lets see if this works: Kubota L3400DT / HST (Dual Traction 4wd / Hydrostatic Transmission) Parts Diagrams

You'll have to provide an e-mail address to view. "Electrical System" on the left side...

ritschner · May 10, 2016

Did you actually replace the two fuses? Sometimes the fuses look and even check out as good but have a fracture that can cause an interuption in the circuit. It is rare, but when it occurs it will stump even the best mechanics because it is intermittent and the fuses still look good. The reason I suggested it is that fuses are inexpensive compared to other components or the labor charge of taking it to the dealer.