Kubota L4600DT starting issue

[bearthebruce]

I'll have to see if I can make a test light or borrow a meter from one of our neighbors. The way you explain it, it seems simple enough. We definitely need to test the seat switch to make sure it is still making a connection. Thank you.

Its worth the trouble to eliminate the seat switch as a cause.

Usually there is a connector on the seat. Just disconnect it and jump the terminals in that connector. See if doing so eliminates the issue.

In my case, I got another housing and pins for the connector, soldered the jumper to the pins. Then, when I need to eliminate the switch because of what I am doing, I unplug the seat, plug in the jumper and off I go.

Most of the time, I want the seat switch working for safety reasons. Hilly terrain, tippy tractor conditions, safety first.

 

[zzvyb6]

Glow plug relay occasionally shorted ? Does "no gauges" mean they are never 'touched' or do they go flat as soon as you hit the key ?
A few guys have used a relay to engage the glow plugs, activated by a separate push-button switch for a work around.

 

[tammyemond]

Glow plug relay occasionally shorted ? Does "no gauges" mean they are never 'touched' or do they go flat as soon as you hit the key ?
A few guys have used a relay to engage the glow plugs, activated by a separate push-button switch for a work around.

No gauges means when the key is turned to the on or start positions the gauges don't move. We first replaced the key switch, because we thought it was bad since the gauges weren't getting any power. That worked for a couple of starts then it started doing the same thing so we replaced the neutral switch and it ran fine for a few days. Then it shut off as soon as it was taken out of neutral. That happened twice and then it's been running fine ever since. Not sure if it's the seat switch or not, I'm going to have Rich (my husband) make a jumper for it. Even if we test it and it test good doesn't mean that it is, it may have a loose connection or a cracked wire somewhere that loses contact sometimes. If it does it again and he jumps the seat switch and it works, it still doesn't mean that it is the seat switch because it's so random. We can't afford to just keep replacing parts.

 

[JC-jetro]

Tammy,

I went and checked the picture library that I have for my Mx-4700. The shuttle neutral switch is not just one switch. They are two switches one for forward and one for reverse. In the neutral position (handle in the notch the switch must be closed. I have couple of picture for your benefit. The strand of wire you see is just a blade of grass.

 

[tammyemond]

Tammy,

I went and checked the picture library that I have for my Mx-4700. The shuttle neutral switch is not just one switch. They are two switches one for forward and one for reverse. In the neutral position (handle in the notch the switch must be closed. I have couple of picture for your benefit. The strand of wire you see is just a blade of grass.


View attachment 815649View attachment 815652

Ours only has one.

 

[JC-jetro]

Ours only has one.
View attachment 815653

very interesting, at least one less sensor to fail. On my Ford 1700 i have only one as I don't have shuttle shift on it. I never needed to do a deep dive on my Kubota as I had just about zero issues in the last 11 years. My tractor has always been parked in the barn as well. I was at the dealer for about 8 hrs that day when they un-crated t and put it together.
make sure the shuttle lever fully engages the rocker arm thing on the switch and connecting two poles of the switch should turn on the test light and and when you push the rocker arm it should turn off. I did go to Kubota site and verified the info as you did.

 

[tammyemond]

very interesting, at least one less sensor to fail. On my Ford 1700 i have only one as I don't have shuttle shift on it. I never needed to do a deep dive on my Kubota as I had just about zero issues in the last 11 years. My tractor has always been parked in the barn as well. I was at the dealer for about 8 hrs that day when they un-crated t and put it together.
make sure the shuttle lever fully engages the rocker arm thing on the switch and connecting two poles of the switch should turn on the test light and and when you push the rocker arm it should turn off. I did go to Kubota site and verified the info as you did.

Neutral switch is new. The new issue was that it shut off as soon as he took it out of neutral. It only happened that one day and now it's been running fine, that's why I'm thinking that there may be a break in the wiring on the seat switch.

 

[JC-jetro]

Neutral switch is new. The new issue was that it shut off as soon as he took it out of neutral. It only happened that one day and now it's been running fine, that's why I'm thinking that there may be a break in the wiring on the seat switch.

Kubota does a very good job on their wiring harness, physical support and wrapping the conductor. Unless there is a visual sign of critter chewing I see low possibility of break, saying that wires can be pulled awkwardly against brush and whatnot as you working the field. Do check the connector and use some spray on contact cleaner and make sue it is blown with compressed air and put back together dry. See if the switch can be adjusted some to have a better contact with the shuttle arm. make sure nothing is bent out of normal. with the tractor off an manipulate the shuttle to see if change of state of the switch works like it should.

 

[JC-jetro]

Neutral switch is new. The new issue was that it shut off as soon as he took it out of neutral. It only happened that one day and now it's been running fine, that's why I'm thinking that there may be a break in the wiring on the seat switch.

I did a bit of digging Tammy,

Attached you can find the configuration of of sensors/switch and relays, such as a controller , flasher unit and glow plug. I don't have WSM for L4600 to see the wiring layout. L4600 is somewhat simpler than Mx-4700. All my sensors is dual but work tandem with OPC (Operator Presence controller) that watches the seat switch. I hope you don't have any issues now but you might have faulty or sticky relay as well. It actually can get a bit complicated. What remain true that they are (sensors) normally closed to complete the circuit before you can start and other fact is when you turn the key to on, it powers up the dash lights like oil pressure light and engine is on indicating intact circuit and then light should turn off after engine is running. That is the same as any automobile. Just some food for thought.

 

[tammyemond]

I did a bit of digging Tammy,

Attached you can find the configuration of of sensors/switch and relays, such as a controller , flasher unit and glow plug. I don't have WSM for L4600 to see the wiring layout. L4600 is somewhat simpler than Mx-4700. All my sensors is dual but work tandem with OPC (Operator Presence controller) that watches the seat switch. I hope you don't have any issues now but you might have faulty or sticky relay as well. It actually can get a bit complicated. What remain true that they are (sensors) normally closed to complete the circuit before you can start and other fact is when you turn the key to on, it powers up the dash lights like oil pressure light and engine is on indicating intact circuit and then light should turn off after engine is running. That is the same as any automobile. Just some food for thought.

Thank you. It's acting up again today. Rich said he turned the key and nothing again, tried a couple of times and nothing, turned it off and was standing there and heard a click and the gauges came up, tried starting it again and nothing everything went dead. I'm starting to think it might be possessed.