B2650 stop then no start.

[DLHam]

Bought new in 2017, first ever issue. Any suggestions on what I may have missed appreciated.
2017 Kubota B2650, 395 hours. Tractor started and mowed fine previous week.

-Started tractor in garage, let idle for a bit. Drove out across yard to start mowing.

-Once engine warmed and at 1200 rpm slid PTO lever forward.

-As PTO engaged, tractor shut off. Disengaged PTO and went to start tractor, no dash lit and no start.

-Found panel/OPC 5 watt fuse blown. Replaced and had dash again but no start. Towed (in neutral) back to garage.

-Found PTO selector safety switch top broke off, PTO engagement safety switch loose/wobbly so got two new switches. Checked and had 12.4 volts across tractor side of connectors to switch.

-Checked seat switch (working).

-Still no start.

-Went ahead and replaced and adjusted the HST Pedal safety as it was quite grungy.

-no start so pulled dash cowling and checked parking switch, it was OK and looked at wiring which appeared fine.

-At this point I put ignition to run and jumped starter and tractor started and all (including PTO) worked fine.

-so if I jump starter all works but not by key.

So is this pointing to bad starter relay?

Many thanks,
Dave

 

[cthomas]

Do you have a WSM? If no, get one. https://kubotabooks.com/AutoIndex/index.php?dir=Tractor Owners Manuals/
Have to verify key is commanding relay to energize. Around 8-S15 page. This is a Cab WSM as your profile does not have what tractor you own(cabbed tractors are cool and hot).........

 

[DLHam]

Do you have a WSM? If no, get one. https://kubotabooks.com/AutoIndex/index.php?dir=Tractor Owners Manuals/
Have to verify key is commanding relay to energize. Around 8-S15 page. This is a Cab WSM as your profile does not have what tractor you own(cabbed tractors are cool and hot).........

Yes, I have the WSM. I hate electronics

I will have a look at that section. My cousin who is an electronics engineer is coming over tomorrow to give me a hand.

 

[DLHam]

Do you have a WSM? If no, get one. https://kubotabooks.com/AutoIndex/index.php?dir=Tractor Owners Manuals/
Have to verify key is commanding relay to energize. Around 8-S15 page. This is a Cab WSM as your profile does not have what tractor you own(cabbed tractors are cool and hot).........

mine is “cab-less” with front loader and belly mower.

 

[DLHam]

UPDATE 08/15/2023

My cousin came over and using his multimeter and other tools we verified:

- all inputs from safety switches were correct for start (HST pedal, park brake switch, PTO engagement).

- Verified key in run position, and verified start signal sent when placed into start position (past glo plug heat).
-verified all wires coming into OPC Timer controller had proper voltage.

- verified from OPC connector down to starter had continuity.

- no start still

-tested voltage at starter where blade connection from OPC timer controller, no voltage when key placed in starter position.

So, it appeared to possibly be OPC timer/controller module. Took it down to Kubota dealer; they said no way to test it but based on testing we did also thought OPC Timer. New one came in, and still no start.

Is there any other relay somewhere we may be missing?

If I use a remote starter switch between the 12V main and blade on relay, starter works fine.

So for some reason still not getting 12v down to starter for some reason?

Using a remote starter is an OK work around but would really want to figure this out.

 

[North Idaho Wolfman]

It's a direct connection from the OPC to the starter solenoid.
nothing else between them.
So if you have power coming out of the OPC starter connection on start and no power at the starter you have a bad wire or connection.
Also make sure you have a good ground connection to the OPC.

 

[DLHam]

Looking at Kubota parts diagram I ran across a starter relay (which we have not touched); anyone know what this is doing?

 

[DLHam]

It's a direct connection from the OPC to the starter solenoid.
nothing else between them.
So if you have power coming out of the OPC starter connection on start and no power at the starter you have a bad wire or connection.
Also make sure you have a good ground connection to the OPC.
View attachment 109320

Yes, thats we saw and thought from schematic. We did verify continuity from wire at OPC down to starter blade, but also that the OPC is not sending a signal out , which is why we replaced OPC.

 

[North Idaho Wolfman]

Yes, thats we saw and thought from schematic. We did verify continuity from wire at OPC down to starter blade, but also that the OPC is not sending a signal out , which is why we replaced OPC.

Did you check to see if it's getting all the right signals in?
Like a start signal from the switch?
Including a good ground to the OPC?
You don't need a fancy meter a simple test light will do it.

 

[North Idaho Wolfman]

Looking at Kubota parts diagram I ran across a starter relay (which we have not touched); anyone know what this is doing?

It's glow plug or stop solenoid relay.
Neither of them has anything to do with it not cranking.
I guess you don't believe the schematic or me, there is no relay between the OPC and the starter!

 

[DLHam]

Did you check to see if it's getting all the right signals in?
Like a start signal from the switch?
Including a good ground to the OPC?
You don't need a fancy meter a simple test light will do it.

Yes, my cousin made a chart of all inputs by wire to OPC and we tested and verified all safety switch inputs, voltage in and ground.

I am still trying to find that starter relay on schematics.

 

[cthomas]

Relay might be within the OPC module.

 

[North Idaho Wolfman]

I've said it three times, there is NO starter relay!

 

[DLHam]

It's glow plug or stop solenoid relay.
Neither of them has anything to do with it not cranking.
I guess you don't believe the schematic or me, there is no relay between the OPC and the starter!

View attachment 109334

I believe you, I am just puzzled that by the WSM all correct inputs from key switch and other safety switches are present and correct yet OPC timer/controller is not outputting voltage to starter per schematic. So puzzled what we are missing. As we had dash/seat off we examined all wiring and found no fraying or pinched wires. Swapping the OPC controller module didn’t fix.

By the WSM it should be cranking.

 

[DLHam]

I've said it three times, there is NO starter relay!

View attachment 109342

Yes I agree, But what does the relay do that Kubota has on their schematics online for B2650 that they call a starter relay ?

once I use remote starter switch tractor runs fine.

 

[Russell King]

Post a picture of the schematic that shows the relay that concerns you. I don’t see anything that says “starter relay“ in the schematics above.

The “starter relay” may be the “solenoid” on the starter?

 

[North Idaho Wolfman]

Yes I agree, But what does the relay do that Kubota has on their schematics online for B2650 that they call a starter relay ?

once I use remote starter switch tractor runs fine.

What online schematic are you looking at?

 

[DLHam]

Post a picture of the schematic that shows the relay that concerns you. I don’t see anything that says “starter relay“ in the schematics above.

The “starter relay” may be the “solenoid” on the starter?

It’s on the B2650 electric online diagrams. Pasting it here.

Post a picture of the schematic that shows the relay that concerns you. I don’t see anything that says “starter relay“ in the schematics above.

The “starter relay” may be the “solenoid” on the starter?

Its listed as part 060, part #RD451-54210 RELAY. Also what is confusing is in WSM under starter troubleshooting it says one possible reason for no crank is starter relay. Hence my confusion.

We verified all inputs on the switch engine start diagram (we even cycled switches to verify they were "on" or "off" as needed), PTO clutch lever switch "on" and HST pedal switch "on" . We got 12V from ignition (key) switch when in run position, got 12V on glo plug position from switch, and got the 12 V to energize starter from switch, but no signal from OPC timer out to starter. So replaced OPC timer but same result.

If I put my remote starter switch to blade on solenoid on starter and main battery line to it, it starts up fine so not starter/solenoid.

So now trying to figure what we may have overlooked. Abut ready to bypass OPC timer for starting position on key :-( (I hate electronics...)

 

[North Idaho Wolfman]

Wanna know the answer to why your getting such conflicting info?


Drum Rolllllllll....

You're looking at the Wrong WSM!
That WSM is for EU units, throw it in the trash!
There is likely a huge difference in the USA WSM and EU WSM for the US models.


And that's not a schematic in the first pic that's a parts diagram, huge difference!

Look at the envelope top right of your screen.

 

[DLHam]

Wanna know the answer to why your getting such conflicting info?


Drum Rolllllllll....

You're looking at the Wrong WSM!
That WSM is for EU units, throw it in the trash!
There is likely a huge difference in the USA WSM and EU WSM for the US models.


And that's not a schematic in the first pic that's a parts diagram, huge difference!

Look at the envelope top right of your screen.

THANK YOU!!!