Electrical Mystery; seeking ideas to account for a sudden stop in all electrical amperage flow on L39

[olympicdog]

Hello all. I've got 206 Kubota L39 with just over 1k hours on it, bought with 400. hrs Have had virtually no issues, and nothing like what I'm about to describe.

Was running around the farm doing a few quick things, had shut it down and fired it up maybe 3 or four times. The last time for maybe 10 minutes max. When I went to start it, it was completely dead.

No electrical current going anywhere. No lights to dash, hazards, coil, lights, nothing

Battery voltage is good, connections at terminals and to ground are good.
All the fuses, big and small are good.
PTO was and is off
Seat safety switch was long ago disconnected.

I disconnected the harness to the key switch, and am not getting any juice to there.

I'm at a loss fellas..... Anybody got any ideas ?

 

[TheOldHokie]

Hello all. I've got 206 Kubota L39 with just over 1k hours on it, bought with 400. hrs Have had virtually no issues, and nothing like what I'm about to describe.

Was running around the farm doing a few quick things, had shut it down and fired it up maybe 3 or four times. The last time for maybe 10 minutes max. When I went to start it, it was completely dead.

No electrical current going anywhere. No lights to dash, hazards, coil, lights, nothing

Battery voltage is good, connections at terminals and to ground are good.
All the fuses, big and small are good.
PTO was and is off
Seat safety switch was long ago disconnected.

I disconnected the harness to the key switch, and am not getting any juice to there.

I'm at a loss fellas..... Anybody got any ideas ?

If you have voltage at the battery and none.at the harness its standard electrical troubleshooting. You trace the circuit starting at the battery and find where it stops. Circuit disgram and voltmeter are your friends.

Dan

 

[Dustball]

Agreed. Your key switch should be getting voltage at all times on one of the terminals regardless of the status of any safety switch or any other switch/button. Find the break in the wiring.

 

[#40Fan]

Wiggle the battery connections.

 

[North Idaho Wolfman]

Check the slow blow fuses (yellow)
I have seen and heard of people swear up and down that they have no power (+) when in all actuality they have no ground (-), just make it look like there is no power.

 

[Nicksacco]

Barring a burnt or broken wire or something like that, I've seen battery terminals corrode just enough to kill all the power. Seems weird after just starting, but it happens.

 

[fried1765]

Check the slow blow fuses (yellow)
I have seen and heard of people swear up and down that they have no power (+) when in all actuality they have no ground (-), just make it look like there is no power.

+1 on the weak/poor ground.....on the machine FRAME!

 

[GreensvilleJay]

Possibly bad battery cables ?
How old are they ??

 

[lynnmor]

Barring a burnt or broken wire or something like that, I've seen battery terminals corrode just enough to kill all the power. Seems weird after just starting, but it happens.

I had that a number of times on my snowmobiles. We had a guy haul them on a special built tractor trailer and it must have rode rough because the batteries were bad at the end of the run. I dissected one to see what was happening and found a break between cells where the link passes thru the partition. The plates were hung from one side only causing fatigue as they bounced. Think how a tractor may give a battery a rough ride.

 

[olympicdog]

Check the slow blow fuses (yellow)
I have seen and heard of people swear up and down that they have no power (+) when in all actuality they have no ground (-), just make it look like there is no power.

It felt like a ground issue to me also, but all the grounds I can find are solid.

I had checked the yellow "slow blow" fuse, and the other three, they all look good, I pulled em all and took a better look just to be sure. They seem fine.

All sound reasoning, thanks to everyone that took the time to offer suggestions !

I guess I'll pull the battery clean and reconnect ... although those connections seem fine.....and start testing from there. If/when I figure out I'll let yall know

 

[olympicdog]

Agreed. Your key switch should be getting voltage at all times on one of the terminals regardless of the status of any safety switch or any other switch/button. Find the break in the wiring.

I did not know that, thank you. Do you know if the hazards are supposed to get amps at all times, regardless of safety switches also ? I seem to remember I could turn those on without a key. Nothing works now.

 

[olympicdog]

If you have voltage at the battery and none.at the harness its standard electrical troubleshooting. You trace the circuit starting at the battery and find where it stops. Circuit disgram and voltmeter are your friends.

Dan

Thanks Dan, I guess that's what it's come to. I was hoping it would be some sort of safety switch. Had one guy tell me there's a safety switch on the clutch ? But should any safety switches cut power to everything ? Hazards, key switch, etc. ?

 

[TheOldHokie]

It felt like a ground issue to me also, but all the grounds I can find are solid.

I had checked the yellow "slow blow" fuse, and the other three, they all look good, I pulled em all and took a better look just to be sure. They seem fine.

All sound reasoning, thanks to everyone that took the time to offer suggestions !

I guess I'll pull the battery clean and reconnect ... although those connections seem fine.....and start testing from there. If/when I figure out I'll let yall know

You check grounds with a contnuity tester.

But if you are not measuring voltage at the harness its more likely an open somewhere in that circuit.

Dan

 

[TheOldHokie]

Thanks Dan, I guess that's what it's come to. I was hoping it would be some sort of safety switch. Had one guy tell me there's a safety switch on the clutch ? But should any safety switches cut power to everything ? Hazards, key switch, etc. ?

would not think any safety interlock would kill power to the instrument panel or lighting.

Dan

 

[PoTreeBoy]

Thanks Dan, I guess that's what it's come to. I was hoping it would be some sort of safety switch. Had one guy tell me there's a safety switch on the clutch ? But should any safety switches cut power to everything ? Hazards, key switch, etc. ?

Safety switches won't cut power to instruments or lights. Key switch may turn most lights off. My bet's on bad ground, master fuse or broken wire.

 

[TheOldHokie]

Safety switches won't cut power to instruments or lights. Key switch may turn most lights off. My bet's on bad ground, master fuse or broken wire.

You can easily eliminate the ground possibility with a voltmeter. Hook black directly to the (-) battery post. Now probe the positive battery connector and verify you get battery voltage. Then probe the harness connector. If no measurable voltage at the connector its not a ground issue.

Dan

 

[Lug66]

Safety switches prevent cranking or running, A quick check out of the main, slow blow, fuse is to do a voltage check at the alternator. The charging circuit is on the opposite side of this fuse. If the battery reads 12.58 VDC then the alternator should read about the same. Red lead goes on the output lug and black lead goes on the alternator case. If you have voltage at the alternator then your problem is after the main fuse(s). If you don’t then the issue is from the battery, cables, main fuse block connection or the main fuse(s) input connection. This easy test answers the voltage question and the continuity question, but it does not answer any amperage questions.

 

[olympicdog]

Gentlemen: Mystery solved. A wiring harness had been detached. I'm not sure how. I did drag some branches along side the tractor..... I find it hard to believe, given all the vertical obstacles to a tiny branch reaching and catching a wire..... but I can't find a more sensible explanation. I'll include a photo of the harness if I'm able taken laying on my back from under the tractor.

In any event thanks to all for the help, I find the existence of a forum like this a veritable silver lining of the internet. But, turns out the system doesn't like the photo "file type". Anyway little harness on top of frame, out of sight, with a red rubber cover like a hot on a battery terminal, not far from the slow blow fuses. Just plugged it back in and back in business

 

[GreensvilleJay]

WHEW !!!! You FOUND the culprit !!! Glad you're now 'up and running' !