Darned thing shut off and wont start again

[Sebculb]

Hello,

I was just working with my Kubota b7610 hst tractor, with a loader and backhoe, and started backing it up a kind of steep awkward hill, using the rear differential lock pedal to get traction. The thing shut off all of a sudden, without making any kind of bad mechanical noise at all. didnｴt sound at all like it stalled out because I forced it; ive done that plenty and its something different. now it wonｴt start again. I kinda have the idea it has to do with some electrical safety switch; Iｴve had similar experiences when the seat on the backhoe attachment would get bumped forward for whatever reason, moving the drivers seat up and disengaging the driver presence switch. So it might be that but Iｴve made sure its engaged as best I can and it wont start. thereｴs a lot of electrical safety switches on the thing, like the pto needs to be turned off and the clutch pushed in for it to turn on, and the driver presence switch in the seat for when the PTO is on. This was one of the first times I used the rear differential lock so I dunno if there is a safety switch there that I donｴt know about, or maybe I used it wrong and broke something... but it didnｴt make any bad mechanical noise it just shut off like when I forget the PTO is on and get out of the drivers seat. The machine is pretty new to me and I have no previous experience with tractors, although Iｴm pretty good with mechanics in general. I thought youｴre supposed to back these things up steep awkward hills. Anyone have any suggestions? 2007, under 300hrs, good condition (except it wont turn on).

Thanks a Lot, really appreciate it

Sebastian

 

[fschukar]

Yep, safety switch. Which one? Don't know. There are at least 3 under the seat and one at every neutral position underneath the machine.
Check each function and watch the "mechanics" if something is not returning to free, neutral that's where the problem should be. I found 5 more on my 2630.
f.

 

[john_bud]

I'd guess the seat switch. That's the usual one that shuts the machine off while running. I think (not certain) that the switch is open to stop and closed to run. Pull the plug and run a shunt wire to bypass the seat switch. If it starts, you know to replace the switch. If it doesn't, pull the shunt and try again (if may be closed to stop and open to run). I would also ohm the plug to see that the circuit is good and there is no rub shorting it anywhere.

If that doesn't do it, then it may be an interlock switch.


If those are all good... could be the ignition switch.

But while it's a PITA, it does sound like a minor issue and not all that expensive. Just time wasting frustrating!

 

[Sebculb]

Thanks guys for the advice. i won´t get a chance to play with the thing again until monday its just sitting out there in the bush for now with a tarp on it. I was wondering which it is to make the switch do its thing, circuit closed to let the tractor turn on or circuit open for it to turn on? But that´s a good point, the trial and error method. It says to never bypass all these safety switches all over the tractor and in the owner´s manual, but it sure is tempting...

I´ll let you know how it goes.

 

[Spikes]

Not proper I know, but this is why ALL 'safety' switches get bypassed on my equipment. Common sense still works. Only ones I haven't been able to bypass are on a Toyota forklift where the computer knows how long it's been disconnected and reacts with limp mode.

 

[Redbug]

My tractor just shut off one day while bush hogging. One of the fuses blew. I don't remember which one. So...be sure to check all your fuses, too.

 

[hr3]

Had the same problem with my 2007,,, 7610 it would die while driving along on rough ground,, I thought it was the seat switch so I bypassed it,, A few weeks later it started doing it again I checked under the seat and ya it was still bypassed,, Then it wouldn't start one day so I took a screwdriver across the starter terminals to get it going,, I tried all the safety switches and every week or so it wouldn't start soooo I put a marine quality waterproof bypass switch next to the starter,, this was about 6mo. ago,, hasn't bothered since I did it go figure I still don't know what it was,,,

 

[john_bud]

My tractor just shut off one day while bush hogging. One of the fuses blew. I don't remember which one. So...be sure to check all your fuses, too.

Good point on fuses!

 

[Sebculb]

Sooo, pretty embarrasing for making all this noise, I went out there today and the thing started right up. After thinking about it for a few days, about "what happened, what changed, why would backing up a slope shut it off?", realized that when the tractor started to pitch forward it pitched the seat forward, and my weight, so even if I was pushing "down" to make sure the driver presence switch engaged, it wasn´t doing it.

Went out there with all the necessaries, (hammer, vise grips, duct tape, tie wire, one of those pointy circuit tester things with the alligator clip and an extra fuse) and the thing must´ve seen me coming and decided to behave properly. I got in the seat and pushed myself back off the clutch and pulled on the side hand rails of the seat to really pull my weight in the correct direction and I guess thats what the under-seat safety switch needed to engage. started on the first try.

Thanks again everyone for all the helpful advice, really appreciate it. I went out there ready to look at all the suggested problems (the hammer and visegrips were a joke). Good to know that the help is there for when something is actually broken.

Keep on truckin´

 

[bandit67]

Yeah, those seat switches can be a pain on hilly terrain. You can always fire it back up after it dies, because the seat switch is designed to only kill the engine when depressing the hydro pedal.

That's a good way to tell if you have a bad switch or a short in the wiring, because the machine will start, but then die when you start to move it. Otherwise, if it's a situation where your weight came off the seat, it'll start back up and move like it should.