Kubota Electrical Problem - Help?

[tnbigal]

Posted earlier on thread that I thought I had this issue figured out:
http://www.tractorbynet.com/forums/kubota-owning-operating/255926-kubota-electrical-problem.html

Symptoms: Getting nothing when key is turned. Lights and flashers won't even turn on. Battery is new, good, and charged. All fuses have been checked and are good. I replaced the ignition switch thinking that was the issue. Problem is intermittent. Once it comes on and starts, it will run fine. Used it all day one day, and then the next day, nothing.

I think I have it narrowed down to one of the relays behind the dash:
110 Relay Glow T1060-33710
020 Unit Flasher 3F240-75430
090 Timer OPC TD060-30500
010 Relay Starter T1060-33720

I guess there could be an issue with a switch or a sensor that feeds these relays. Just hard for me to understand which of the above would keep the lights/flashers from even coming on. The Electrical Manual shows the relays, location, and part number, but doesn't give an explanation on the relay function or what each wire on the relay represents.

A couple of the relays above that I suspect are the issue cost 75 each. I've already replaced the 50 dollar ignition switch and that wasn't the issue. I just don't want to keep throwing money at it.

 

[tnbigal]

I thought I would add, I checked for chewed, cut, or frayed wires at the connectors on each of those relays. Also cleaned the contacts.
None of the dash lights come on, and I don't hear any of the usual sounds or clicks that you normally get when turning the key.

This model has a seat safety switch, but not a seat tilt switch.

 

[BeezFun]

Since you say the lights won't turn on, I'd start there. Go to light and see if there's 12v, if there is but the lights not on it's a bad ground somewhere. Run a jumper wire from the negative post of battery to that light and see if it comes on, if it does, it has to be a ground problem. If no voltage at the light, work backwards until you find 12v. I'd take a wild guess that there's a bad ground somewhere that is affecting lots of things, hard to imagine anything else causing so many different problems. Follow the battery ground and check where it's attached.

 

[tnbigal]

Thanks, Beez. I had started doing just that a week ago. Everything seemed to be good, and that's when I finally jiggled one of the relays and it energized and started. Used it twice and it worked fine, now back to having the issue.

One thing I did notice was that even when it would crank and run good, it would sometimes shut off when I got out of the seat, and this was without the PTO engaged and the tractor in neutral. I guess I'll keep digging.

 

[Gordon Gould]

I would check the PTO safty switch and Neutral sensing switch. Both electrical and mechanical activation levers. Sounds like your seat switch works but one of the others could be intermittant

 

[dstig1]

There is rarely an easy solution to electrical troubles. If you have a voltmeter and the schematic, that is the place to start. In a nutshell: Find out where there is 12v, and where there should be 12v but isn't. Once you do some detective work there, it should become clear where the problem is - "between here and here". And like a previous poster noted, if you see 12V where you should, but still have nothing, then start tracing grounds. As you have already found out, do NOT replace a part until you can verify it is bad. Sometimes you take the obvious easy way (like you did with the ignition switch), but you don't want to keep doing that. For example - When you think a relay is bad, pull it out and test it both energized and open. Does it do what it should? If so, then the relay is good, and the problem is elsewhere.

That said, the safety circuits are probably where I would look first.

Good luck.

 

[tnbigal]

Good advice. I wish i had a good schematic, but the Electrical manual that shows the layout isn't what I'd call good. Hopefully this week I'll get some time to dive back into it.

 

[dstig1]

Have you asked the guys from Messicks for the schematic? I hear they will fax or email you copies as needed.

 

[stoyan79]

Wiggle the HST pedal back and forth when turning the key, I had the same issue with my L3700 and the HST pedal was out of adjustment. Fairly common on these.