RX 6620 CAB - ELECTRICAL NIGHTMARE

[Greg Peak]

It's been a great tractor for 7 years, Suddenly it kept falling out of forward, also if I touched the brakes it would die and lose all power for 30 minutes to hours and suddenly all power would come back on, If I turned on the headlights it instantly dies and loses all power for hours to days, If I use the PTO and then turn off the tractor and try to start it right after however all Power is dead for hours or days. Had it hauled to the dealer, 3.5 months and $4500 later they replaced the transmission controller, a 3' wire harness that connected to the controller and installed a new battery. When they finally returned it I drove it 800' and seemed to work fine until I found they fixed nothing else. They sent their mechanic out who said he was the one that did all the work, then he admitted he hates this tractor, hates electrical and has no idea what's wrong that he generally only works on hydraulics, and said they zero support from the factory Rep!!! Dealer texts me the next day and says they will pick it back up. I have more knowledge then their mechanic which is no much and I hate to let them have it back! Has any one had this kind of power loss happening to their Kioti because this dealer has no clue???? Thanks for any help
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[Ridgeline Farmer]

I have never had this type of problem, yet. I do understand electrical gremlins can be a nightmare. I will offer my thoughts and take them for what you will. I am NOT a professional.

1. Verify battery is good, load test it. Check terminals are tight and clean. Verify ground to the chassis is tight and clean.

2. Start tractor, verify alternator is actually charging battery.

3. Inspect fuse block. Check that back of block all wire connections are clean and tight. Pull all fuses one at a time and verify good and reseat.

4. Check wiring harness, no chaffing or wires chewed through. Where the wiring terminates, check wiring to back of connectors look good then unplug connector, look for corrosion and reseat. Make sure all chassis grounds are clean and tight.

5. Check ignition module is good and check any safety interlocks are operating correctly.

6. Beyond this I am not sure. Check computers? I hope I understood your problem correctly and that my suggestions will provide some help. I fully understand how frustrating stuff like this can be.

BTW, Happy Thanksgiving, here's to hoping you get your tractor figured out!

 

[Ridgeline Farmer]

Another option, when the tractor dies next time, leave everything as is (key on) and check voltage on battery, that it is good. Then trace your 12VDC power up the line until you find where it stops. I.E. there may be a faulty relay that is going bad. Also, you can check for power at the fuse block and trace that out. I am sorry that this suggestion is very vague but without a wiring diagram it's hard to visualize where power is coming from and going to. This part I don't believe would be too hard, since with random nature of your problem I don't believe everything is acting up only certain points that distribute the voltage. Again, hope this provides some help. Hopefully someone with more knowledge will chime in with some better answers.

 

[Greg Peak]

It's been a great tractor for 7 years, Suddenly it kept falling out of forward, also if I touched the brakes it would die and lose all power for 30 minutes to hours and suddenly all power would come back on, If I turned on the headlights it instantly dies and loses all power for hours to days, If I use the PTO and then turn off the tractor and try to start it right after however all Power is dead for hours or days. Had it hauled to the dealer, 3.5 months and $4500 later they replaced the transmission controller, a 3' wire harness that connected to the controller and installed a new battery. When they finally returned it I drove it 800' and seemed to work fine until I found they fixed nothing else. They sent their mechanic out who said he was the one that did all the work, then he admitted he hates this tractor, hates electrical and has no idea what's wrong that he generally only works on hydraulics, and said they zero support from the factory Rep!!! Dealer texts me the next day and says they will pick it back up. I have more knowledge then their mechanic which is no much and I hate to let them have it back! Has any one had this kind of power loss happening to their Kioti because this dealer has no clue???? Thanks for any help
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UPDATE! Well the tractor 100% died at an idle and again with a total loss of power, so I rechecked and tested all fuses and all were good , pulled every relay and bench tested each one and all were good. Then stared back tracking power from the battery to everything up front until I checked the power going into the brand new ignition switch and found it only had a flickering 2 volts. I traced the harness down to below the floor, removed the access plates on the floor and found the main power connector along with 4 other large connectors. See the attached pic of the inside of the plug, the male and female main power connector is completely destroyed. There was no die-electric grease inside nor is there any grease in any of the other plugs.

Since I can't find any male and female connecters that are this big to replace them inside the plugs and these wire harnesses cost thousands each I'm just cut off the two plug ends and solder the three wires together and use shrink tape which wont cost me anything.

For all of you with Kioti tractors I highly recommend you check and open every single wire harness connector and make sure they have die-electric grease in them because moisture or humidity is getting in these plugs and you will save yourself from this nightmare!

 

[5030]

Candidly, I don't know of any OEM that puts grease in any Molex connector, They are all connected dry.

They are 'O ringed' to keep moisture out but most eventually leak anyway.

Both my Kubota's are basically mechanical but they still have electric systems and one thing I did years ago was I pulled every connector in the harness and packed each and every connector, Molex style or not with Di-Electric grease, especially those exposed to the elements and I've never had any electrical gremlin's at all.

I also keep all the main electrical connections from the starting battery to the main frame grounds clean and free of corrosion and I coat them (after cleaning) them with Fluid Film but you can use any corrosion preventer.

Finally, I always break the battery out of circuit when sitting idle with a mechanical breaker (you dan buy them at any auto parts store) on the NEGATIVE battery post. That removes the battery voltage entirely from the electrical system and I change out my starting batteries at the first sign of slow cranking which in my case, seems to be around 3 years. I replace them but before I install a new battery, I trickle charge it to full capacity before installing.

Seems to me that electrical systems and starting batteries work until they don't and are almost always neglected and that includes your buggy, not only your tractors.

My oldest Kubota is a 2002 and never an electric issue with it.

Do I like replacing starting batteries, nit really. Both my Kubota's require Group 31 batteries with at least 900 CCA and they aren't cheap by a long shot but I'd rather have batteries that will start them right up than have a going south battery that won't and they both reside in an unheated barn with no electrical service to plug them into or even jump start them.

Nice aspect of breaking the starting battery out of circuit is, if there is any sort of electric drain on them, they aren't impacted at all and the state of charge remains what it was when I parked them until I put the battery back in circuit and cold start them.

How I do it and always will. Your mileage may vary but I know what my mileage is....

 

[5030]

I might add that I 'converted' all the conventional filament bulbs to LED's and that includes the work lights as well as the instrument panel lights and even the headlights in the grill. LED's have a much lower current draw and are much easier on not only the alternator but the battery as well.

Converting the LED work lights allowed me to double the work lights and still not overtax the electrical system. My Kubota cab unit now has 4 high mount LED work lights forward and 2 rearward with at least 3 times the illumination that was present when I purchased them.

I'm 100% sold on LED lights versus conventional filament lights. They last longer as well, in fact, much longer.

 

[MichiganIron]

Both my Kubota's are basically mechanical but they still have electric systems and one thing I did years ago was I pulled every connector in the harness and packed each and every connector, Molex style or not with Di-Electric grease, especially those exposed to the elements and I've never had any electrical gremlin's at all.

Dielectric grease in Main Power Connectors only. Do not use any Dielectric Grease in any of the engine ECU Sensor or Actuator Plugs. Many of these connection carry low voltage communication signals and CAN Network communications with the ECU. Dielectric Grease can cause issues with the ECU Communication Network.

 

[LouNY]

I would not hard wire those wires, I would replace the connector with other weather proof connectors of one of the many brands out there.

 

[5030]

Both my Kubota's are basically mechanical but they still have electric systems and one thing I did years ago was I pulled every connector in the harness and packed each and every connector, Molex style or not with Di-Electric grease, especially those exposed to the elements and I've never had any electrical gremlin's at all.

Dielectric grease in Main Power Connectors only. Do not use any Dielectric Grease in any of the engine ECU Sensor or Actuator Plugs. Many of these connection carry low voltage communication signals and CAN Network communications with the ECU. Dielectric Grease can cause issues with the ECU Communication Network.

In my case they don't exist simply because both of mine are mechanically injected with no emissions crap I don't want anyway.

 

[5030]

I would not hard wire those wires, I would replace the connector with other weather proof connectors of one of the many brands out there.

Digikey for one offers them in many configurations.