kubota 2501 won't start

pan84shov · Mar 19, 2022

Tractor was running, but after shutting it off it wouldn't start. Happened once before but after jiggling wires around it started. But this time, nothing happened. I removed the starter and bench tested it, and it was OK. Voltage was good at Battery and at Large terminal on starter. I ran a jump wire from the small terminal on the starter to the battery and it started. Still won't start with the key. Could this be a faulty ignition switch? 120 hours on tractor. I assume the small wire (with a single plug) where I jumped it comes from the ignition switch?

Jstpssng · Mar 19, 2022

Does it turn over and not start or does nothing happen when you try to engage the starter? If it's the latter it's most likely a safety switch. If it's HST try moving the rocker pedal up and down. Also the PTO engagement switch, especially if you were using it when you shut it down. That can be a PITA if it's stuck on a high spot, so that the safety switch won't disengage.

Henro · Mar 19, 2022

pan84shov said:
Tractor was running, but after shutting it off it wouldn't start. Happened once before but after jiggling wires around it started. But this time, nothing happened. I removed the starter and bench tested it, and it was OK. Voltage was good at Battery and at Large terminal on starter. I ran a jump wire from the small terminal on the starter to the battery and it started. Still won't start with the key. Could this be a faulty ignition switch? 120 hours on tractor. I assume the small wire (with a single plug) where I jumped it comes from the ignition switch?

Sounds like a safety interlock circuit issue.

You essentially confirmed this when you jumpered from the starter main power lug, to the terminal that the safety interlock circuit connects to.

You need to get a workshop manual, or at least a wiring/schematic diagram, to determine how many safety interlock switches are there, and then check them all.

You also could have a wiring problem in the safety interlock circuit...poor connecting to any of the switches, or a broken piece of wire between the switches...etc.

Edit: As poster #2 said, moving the various functions that might be in the safety circuit (when the key is turned to the start position and held there) is a good idea too.

pan84shov · Mar 19, 2022

Jstpssng said:
Does it turn over and not start or does nothing happen when you try to engage the starter? If it's the latter it's most likely a safety switch. If it's HST try moving the rocker pedal up and down. Also the PTO engagement switch, especially if you were using it when you shut it down. That can be a PITA if it's stuck on a high spot, so that the safety switch won't disengage.

Won't turn over at all. When the switch is turned on it will cycle the fuel pump. haven't used PTO lately. Will try the Rocker Pedal, cause it is an HST. Thanks!

pan84shov · Mar 19, 2022

Henro said:
Sounds like a safety interlock circuit issue.

You essentially confirmed this when you jumpered from the starter main power lug, to the terminal that the safety interlock circuit connects to.

You need to get a workshop manual, or at least a wiring/schematic diagram, to determine how many safety interlock switches are there, and then check them all.

You also could have a wiring problem in the safety interlock circuit...poor connecting to any of the switches, or a broken piece of wire between the switches...etc.

Edit: As poster #2 said, moving the various functions that might be in the safety circuit (when the key is turned to the start position and held there) is a good idea too.

Only Checked the safety interlock, under the seat and on the clutch pedal. . Glad Jstpssng mentioned the rocker pedal. Don't know of any others. Your spot on about the Wiring/Schematic diagram. I will check on getting one getting a wiring diagram. Thanks!

pan84shov · Mar 19, 2022

Update! The suggestion from Jstssng about moving the rocker pedal up and down while cranking did the job! Fired right up when I moved it. I really appreciate the knowledge yall give on this site! A BIG THANK YOU!!!!!!

Jstpssng · Mar 19, 2022

pan84shov said:
Update! The suggestion from Jstssng about moving the rocker pedal up and down while cranking did the job! Fired right up when I moved it. I really appreciate the knowledge yall give on this site! A BIG THANK YOU!!!!!!

Good deal! It's always nice when things are a simple fix... especially when you find them BEFORE trying to address something more serious. (read, expensive.)

Not that I would know anything about that!