G1800 will not turn over

[cwhiley]

I’ve got a g1800 with 884 hours in it and it will not start. It used to be intermittent but it’s gotten a lot worse. I’ve not been able to start it all now in about 6 months. I just hear a rapid clicking but it will not turn over. I did try shunting the 12 volts straight into the starter bypass the starter selenoid and the starter spins but it still won’t turn over.

I’d really like to avoid a $500 something bill at the dealership…but I don’t know what to even look at. I did also short the safety switch on the seat with a wire but it made no difference.

I do know how to use a multimeter to check voltages and resistance ohms but I don’t know what to look at.

If anyone has any ideas to try explained very simply I’d really appreciate any help you folks could give.

Thank you so much!

 

[GreensvilleJay]

1st step... get the wiring diagram for it ! usually found in the WSM ( WorkShop manual), though www.kubotabooks,com don't list one.....
Without that you can spend hours tracking down the faulty 'safety' switch or 'interlock' switch that is preventing the starter from spinning when you turn the key.
Hopefully someone can post the diagram here for you.

 

[Hugo Habicht]

What do you mean by "starter spins but it still won’t turn over."?

I interpret that as the starter solenoid not engaging the pinion into the flywheel.

Did you short the 12V to the fat rotor current contact or the small starter solenoid contact?

 

[Hugo Habicht]

There is three safety switches (brake, pto, seat) that affect the starter through the combination box.

Often the relais in the combination box are burnt out, leading to the starter working intermittently and then not at all. My tractor had that problem at 6000 hours, yours seem a bit young for that but it is starting cycles really, not hours.

Also it could be the start switch contact itself.

Click on the envelope, top right corner of the screen.

 

[cwhiley]

What do you mean by "starter spins but it still won’t turn over."?

I interpret that as the starter solenoid not engaging the pinion into the flywheel.

Did you short the 12V to the fat rotor current contact or the small starter solenoid contact?

I mean I can hear the starter spin up but nothing else happens. Just a whirring starter. I shunted the connection on the bottom of the assembly that connects to the battery up and over to the top. Honestly no idea what I’m doing but the starter definitely spun up. I couldn’t sit on the seat to do this so I shorted the seat sensor with a wire and I pushed the brake pedal down.

 

[cwhiley]

There is three safety switches (brake, pto, seat) that affect the starter through the combination box.

Often the relais in the combination box are burnt out, leading to the starter working intermittently and then not at all. My tractor had that problem at 6000 hours, yours seem a bit young for that but it is starting cycles really, not hours.

Also it could be the start switch contact itself.

Click on the envelope, top right corner of the screen.

yea I’ve read about the combination box and suspect that $330 part.

 

[Mark_BX25D]

You need to do some actual testing. Find out what voltage is getting to what terminal at the starter.

You will probably need an assistant to turn the key while you take voltage measurements.

 

[North Idaho Wolfman]

I mean I can hear the starter spin up but nothing else happens. Just a whirring starter. I shunted the connection on the bottom of the assembly that connects to the battery up and over to the top. Honestly no idea what I’m doing but the starter definitely spun up. I couldn’t sit on the seat to do this so I shorted the seat sensor with a wire and I pushed the brake pedal down.

First: You simply jumped the starter wrong, you need to jump from the large terminal with the battery cable to the small terminal usually with a spade terminal on it.

Do that with the key on and see if it will crank and fire, that will tell us where you need to go next.

 

[whitetiger]

Here is the starting circuit.

 

[lmichael]

Kubotas have very convoluted circuitry to the starter. Roya PIA IMO. Too much current trying to get through microswitches. You can likely clean likely clean every contact and connection, relace all the microswitches and still have the issue. Likely a helper relay will solve all your issues as it did mine.

 

[Hugo Habicht]

yea I’ve read about the combination box and suspect that $330 part.

Yes, I had that problem and built my own combination box electronics: Link combination box electronics

But lets diagnose the problem first, there still is the starter solenoid and the three safety switches to check.

Did you click on the envelope in the top right screen corner?

 

[pigdoc]

On my current G1800S, I have had a long-standing 'problem' on starting.

There is also a start-safety switch on the brake pedal. If you don't have the pedal locked in the full down position (fully applied), starter will not energize when the key is turned.

Full down: If you gently hold the brake pedal lock while you push the break pedal down, you will feel three detents. You have to keep pushing the pedal down until you feel 3 clicks in the locking lever. Then, the starter cranks, even if the battery is too low to start the tractor.

So, check the wiring to that brake pedal safety switch.

-Paul

PS, I haven't yet looked to see if I can adjust the brake pedal safety switch. That's on the list.

 

[Hugo Habicht]

PS, I haven't yet looked to see if I can adjust the brake pedal safety switch. That's on the list.

Yes, brake switch can be adjusted. Brake switch is normally closed while the PTO and seat switches are normally open.

The insides and how to repair a brake switch you find here: Link G1900 brake switch repair

 

[Mark_BX25D]

Kubotas have very convoluted circuitry to the starter. Roya PIA IMO. Too much current trying to get through microswitches.

The microswitches carry very little current. Yes, they are potential failure points, but current is not the problem.

 

[Hugo Habicht]

Kubotas have very convoluted circuitry to the starter. Roya PIA IMO. Too much current trying to get through microswitches.

They are not microswitches, see link in post #13. And the current through the switches is very small. The starter current is going through a power relais, so is the stop solenoid current.