Kubota G1800 won't shut off

another help spot maybe?....Combo Box G1800 - OrangeTractorTalks - Everything Kubota

I say try to crack the combo box open and replace the failed part. My 93 mustang has an Integrated Relay Control Module (IRCM). They hid the fuel pump relay in there. It was a basic 12v 30A bosch and I was able to remove the old one and solder in a new one. It sure beat paying $150 for a whole new box.

Going to go to the local Kubota dealer and see if I can get a better electrical diagram. Guess I will take the time to pull wires and see if I can find a broken, rubbed, shorted, etc. wire...just didn't really want to do it but oh well. KennyV and reddragon - I really should just put in a separate kill switch. It would be easier and cleaner, but I'm just twisted that way. :laughing: I plan to start at the connector right before the shut off solenoid and work backwards.

reddragon - thanks for taking the time to call the kubota mechanic. I really do appreciate that. It does make me feel somewhat better that it's a pretty common thing to go bad. Like you also said, it doesn't make me feel better that Kubota would put their electrical components in such a "mystery" box. I really should take the advice to put in a separate switch! And I just may do that.

djrussell - I just can't see how I could break into that box without really messing things up. If you look at the pic, you can see that the material surrounding all the connections, wires, etc. is a molded epoxy type material. Not sure exactly how that would work. However, if I come to the conclusion to bite the bullet and get a new combo box, I may just go for it and see what happens.

Thanks for all your advice guys. I'll let you know what I find out. If you have any other thoughts, please keep the posts coming.

Went to local Kubota dealer and spoke to parts person as well as the service manager. Found out the combo box is $155 + tax (OUCH :frown. Hope to find it cheaper online. Does anybody have recommendations for a reliable parts place online?

Service manager stated the combo box was probably the culprit. Stated the relay that powers the ESS is indeed in the combo box. Also told me that in order to replace the combo box, need to unwrap the electrical bundle to the first connector (behind the radiator screen), disconnect the old, connect the new and hope that solves the problem.

Before I do that I plan to purchase a 12V DC test light and see if I can trace any voltage out of the combo box to the ESS. However, as another test I tried to see if any of the safety switches would shut down the mower. I have not disabled any safety switch. I was able to start the mower without sitting in the seat. I then tried to start the blades on the mower deck (still not sitting on the seat) and the blades started turning just fine and the mower just kept running. That should have shut down the mower right? I wonder if the relay in the combo box also affects these safety switches where they won't work? Does this test mean anything?

wow...you've been in hot pursuit of this problem!...good job!.....pto switch/brake switch and almost everything else goes thru that damn thing....yes the seat switch should shut them down....but might allow for starting....i hate to say it...[because it goes against my budget minded ethics] ..but that combo box should be replaced just for preventive maintenance:frown: at this point.....can you give me the year? and model serial numbers of the mower and engine? and ill see what i can scrounge up for box prices for you...:thumbsup:

Unfortunately, I must agree with you reddragon. This mower is old in years but not in hours. It only has 382 hours on it...my dad bought it new and gave it to me after he decided he couldn't live w/o a zero-turn mower. My gain. :tongue:

The mower serial number is 11277. I think that makes it a 1989-1990 model.
The engine serial number is 201401 (I think). On the left side of where these numbers are located is D662 (the engine model #?) and 201401 (the engine serial #?) is on the right side.

THIS MIGHT BE IT....KUBOTA BOX COMBINATION (PART#: 66101-55920) THAT COLEMAN LINK EARLIER IN THE THREAD

mrficxit said:

djrussell - I just can't see how I could break into that box without really messing things up. If you look at the pic, you can see that the material surrounding all the connections, wires, etc. is a molded epoxy type material. Not sure exactly how that would work. However, if I come to the conclusion to bite the bullet and get a new combo box, I may just go for it and see what happens.

Click to expand...

I understand the pic now. I didn't see that on first glance. Since you're headed down the replacement path anyway, you could try to disolve the sealant or cut it away. I'm not sure what material you've got there but there are chemicals that will eat it. I've heard that gas can dissolve silicone. I remember some capacitors would get an epoxy coating that may be different though.

It's really stupid that the connection to this box is so far away. That's bad design IMO. If you're lucky you may find a connection under the sealant and the wires won't be soldered to the board.

it looks busted up too

dj - I couldn't agree more about the bad design. Red, it is busted up, pretty badly IMO. Why Kubota would put a bunch of relays, capacitors, and who knows what else in a potted environment where you can't get to it is beyond me. And then they have the insight to bolt this item directly onto a metal plate attached to the frame and engine of a diesel, which shakes, rattles and rolls, without putting any kind of dampening bushings or anything. I guess they thought that if they put all this sensitive electrical stuff in this epoxy stuff, that the epoxy would provide the necessary dampening. Based upon reddragon's and my conversation with Kubota mechanics, that was a bad thought. We were told these mystery boxes fail quite a bit. And then to put the connector to this box so far away, adds insult to injury.

I love Kubota stuff...it is well made, but they messed up on this. But my mower is over 20 years old and I've not had much, if anything, go wrong with it. But, I also have very low hours on mine. All in all though, this isn't bad, just inconvenient. If and when I do buy another combo box, I'm going to try and see if I can add to the dampening ability. Maybe put some rubber bushings between the combo box and metal plate??