Kioti LB1914 30 amp "slow blow" fuse burned twice - can't find cause

[Missouri Kioti]

Hey all, Used my LB1914 tractor just yesterday to move some stuff with the bucket. Started and shut if off several times, no issues all day. Parked it that night, went to start it this morning... and nothing. Didn't have power to anything, no dash lights, no glow plugs, not even headlight would turn on.

Took battery out load tested good with full voltage and CCA. Removed, checked and cleaned the cables and terminals. Made sure ground cable had a good connection. Reinstalled still nothing.
Checked fuses on/under dash, all were good. Checked visible wiring, didn't see anything burned or chewed.

Finally found the 30 amp fuse by the starter, pulled it and it was blown. Drove to town... realized when I got to the register I had forgot my wallet .... drove back home and back to the autoparts store again which cost me an hour and probably more $ in fuel than the fuses cost... bought two new fuses which is all they had in stock.

Installed first one, NO key in ignition and nothing on. Seconds after I installed it saw some smoke coming up from under the hood in engine compartment closest to the backside of the dash. Fuse finished blowing and smoke faded away before I could get around to the other side of the tractor to see where it was coming from.

Does anyone know what the 30 amp "slow blow" fuse by the starter actually goes to?
Have tried to find a wiring diagram but have come up empty.

I don't know if there is a short somewhere that I just can't or didn't see. Or if there is a component like the regulator that is fried or something.

Any ideas? All input is much appreciated.
Thanks

 

[skipmarcy]

In automotive repair I had several different capacity circuit breakers made up with pigtails with the spade terminals that are the same size as the spades on the fuse and used them to keep from wasting so many fuses in diagnosis. By the sounds of it though you'd better be careful if you let some of the smoke out - be ready to pull your tester out if necessary.

 

[Missouri Kioti]

In automotive repair I had several different capacity circuit breakers made up with pigtails with the spade terminals that are the same size as the spades on the fuse and used them to keep from wasting so many fuses in diagnosis. By the sounds of it though you'd better be careful if you let some of the smoke out - be ready to pull your tester out if necessary.

Thats a good idea. I got some circuit breakers, might make up a fuse saver. And yeah, will have to watch. if its a component, well its already fried and isn't working. Wouldn't worry if it smoked some more, at least I would know what is smoked. But if its a wire buried somewhere, I certainly don't want it melting and burning more wires with it, especially if its inside the wiring harness. Going to see what I can find today... wish I could pull the tractor into my garage out of the heat, but don't have any way to raise the backhoe

 

[lpakiz]

Here's another variation on the circuit breaker strategy--use an old sealed beam headlight in place of the fuse. The headlamp will pass about 4-5 amps---safe for all but the smallest wire or most delicate switch terminals.
You can also put the sealed beam in "series" with an unhooked battery cable and battery post, and even a 10 amp fuse (or circuit breaker) will safely pass the 5 amps that the headlight allows thru.
If the light glows brightly, with no obvious extra calls for power, your short is in full force and effect!
NOW go to the suspected area of the short and investigate. Take your time, nothing is being damaged. Unplug and reconnect components until the intensity of the light changes. When that happens, you will have found the short.
Keep in mind that even a dome light will cause some power to flow thru the headlight filament. A bit more call for power could result in a small, dim "glow" from the filament, but a dead short (Smoke!) will cause the filament to glow brightly.

 

[Missouri Kioti]

Here's another variation on the circuit breaker strategy--use an old sealed beam headlight in place of the fuse. The headlamp will pass about 4-5 amps---safe for all but the smallest wire or most delicate switch terminals.
You can also put the sealed beam in "series" with an unhooked battery cable and battery post, and even a 10 amp fuse (or circuit breaker) will safely pass the 5 amps that the headlight allows thru.
If the light glows brightly, with no obvious extra calls for power, your short is in full force and effect!
NOW go to the suspected area of the short and investigate. Take your time, nothing is being damaged. Unplug and reconnect components until the intensity of the light changes. When that happens, you will have found the short.
Keep in mind that even a dome light will cause some power to flow thru the headlight filament. A bit more call for power could result in a small, dim "glow" from the filament, but a dead short (Smoke!) will cause the filament to glow brightly.

I'll have to remember this one! Gives more feedback info than other things I've used. Thanks for the post

 

[Missouri Kioti]

Ok, here's the update: I made a 30 amp circuit breaker "tester" this morning to replace fuse temporarily, I thought I had more circuit breakers but could only find a 30 amp. When I connected the battery cable, it took about 20 seconds before the the magic smoke started to appear. It was coming from the regulator, which is what I was suspect of when I saw the smoke yesterday, as it was located around the right area where the smoke seemed to have came from. In the 3rd photo below on the backside of the regulator, you can see some cracks in the sealant/epoxy. Also around the wires as well.

Now my concern is if it is just the regular that went bad due to internal corrosion or etc causing a short. OR is there something else that shorted and in turn fried the regulator.

So far I have not found any other wires that are bad or anything. Even the wires going into the regulator are not burned or etc. So at the moment I am hoping it was just a bad regulator, and that when I replace it the new one won't also burn

Looks like the regulator is $85 to $100. Found it for $85 on Tractor Joe's:

https://www.tractorjoe.com/parts/p/76704-64601-regulator-10/mt/tractor/b/kioti/m/lb1914/?c=187&sc=6455

What do you all think? Just a bad regulator??

 

[lpakiz]

If and when you get a new regulator, i would unhook the positive battery cable before installing the regulator. Then I would hook the previously mentioned seal beam headlight between the battery post and the cable, thereby limiting the maximum amps that are available to fry the "smoke" out of a component.
Keep in mind that even the headlight strategy could pass enough amps to fry the new regulator, so no guarantees from me, but it would be better than giving the new regulator full battery amperage, which runs in the hundreds of amps.
Again, if the headlight glows pretty bright, I would hesitate to re-hook the battery cable direct until I could get that headlight to a dim or even no glow.

 

[lpakiz]

And remember, your goal is to get that headlight bulb to glow pretty dim, if at all. If it's still bright, unhook some of the leads to the alternator to see how that affects the bulb. It could be that there is a problem in the ALTERNATOR itself, short circuiting to ground THRU the regulator.

 

[Missouri Kioti]

And remember, your goal is to get that headlight bulb to glow pretty dim, if at all. If it's still bright, unhook some of the leads to the alternator to see how that affects the bulb. It could be that there is a problem in the ALTERNATOR itself, short circuiting to ground THRU the regulator.

Yeah, thats a good idea. I'll try that and see what happens when I get a new regulator. I replaced the alternator a couple years ago when the original would [Not] charge any more. But anything is possible.

 

[Missouri Kioti]

thought i would post an update, didn't want to leave this thread without a resolution.
replaced regulator with an aftermarket, power restored. used the tractor for a bit today, seems to have fixed the problem.

https://amazon.com/dp/B005CXZGSQ?psc=1&ref=ppx_yo2ov_dt_b_product_details