B8200 fusible link smoking

[squarethumps]

I'm having an issue with my B8200 ( clutch, D950 ).

When I try and start the tractor, the fusible link starts to get hot and smoke. ( I stop before it burnt out completely )

I think that if I were to replace that fusible link, the same thing would happen with the new one.

The question is : The fusible link seems to protect everything on that side ( the key switch and everything it is connected to ) so how can I figure out what the REAL problem is ? I've replaced the key switch already because I thought it was bad, but I'm still getting the same symptoms.

At first, I was receiving 12v at the key switch through the red wire, and then, when I would simply turn the key to the RUN position, the voltage on that wire would disappear. I cleaned up the battery ground to the rear axle, and then I cleaned up the starter solenoid nut and ends that both attach there ( the battery positive cable, and the red wire which carries power to the ignition switch ). After doing that, I am now getting power to the key switch when I turn the key to the "RUN" position. But now ( as I said ) when I try to start it, the fusible link gets hot and starts to shoot smoke out of a hole it has burned for itself in the link wire cover. ( The starter does not turn over at all like this ... I've tested and jumped 12v directly to the starter itself and it will turn the engine over ).

Is there something on one side or the other that would be causing this ? The starter solenoid ? The voltage regulator ? Is it simply a bad fusible link that needs replaced ?

I'm just not quite sure what to test or change out.

Many many Thanks.

 

[85Hokie]

For the fusible link to get that hot and smoke, you have a short-circuit of something going on to place that many amps to that spot.

I agree with you - replacing it may simply repeat the smoke. Once it has been burnt - it does need to be replaced. So I am gonna say, when you replace it, buy 2 of them!

Somewhere there is a complete circuit from hot to ground - trace the red wire from fusible link to starter and back to switch, any chafing or broken insulation that could be hitting ground? Any chance one of those red wires near the starter are bent over touching ground

When was the last time it started correctly?

 

[squarethumps]

I had it running fine the one day, and then I shut it off for a while and tried to start it again. In order to start the tractor, I have to use the glow plugs every single time, even if the tractor has only been off for 10 minutes. Anyway I was using the glow plugs and all of a sudden the glow plugs indicator started glowing brighter than ever .. like almost white ..it seemed like Sparks were coming from behind the indicator ... So I immediately stopped doing that and let it sit. Then nothing.

I cleaned out cobwebs and dirt and dust behind the console which I thought might have caused that crazy behavior.

I suppose it's possible that the red wire has a short under the fuel tank somewhere, but it's not visually melted, and everything is still all taped up in that area. I removed the tape near the starter and up to the *firewall. Then I cleaned the connector that is under the fuel tank. ( Wow was that filthy and gummed with crap. )

My flasher switch also has always been temperamental, and now doesn't seem to work at all ( I can hear it trying to work). The lights work ( now that I've cleaned up the terminals and again have power to the key switch.)

The wires under the tank around that connector might be the problem I suppose ....? I will take the tape off all those wires tonight and see if I can see any damages.

 

[squarethumps]

I found the wiring diagram in the B8200 Owners Manual file I have ( .pdf .. readily found on the web, oddly enough ), and attached it.

It seems that the 15A fuse ( Red wire -- 15a fuse -- Red / White stripe ) .... there was a 14a fuse in there ( shouldn't be a problem ? ) but it crumbled when I tried to remove it. The metal end of the fuse was stuck inside the plastic fuse holder, and it seems as though it got hot, as the plastic fuse holder is stained dark brown in the spot where that end of the fuse rests. It took a little scraping on the inside of the fuse holder to release that end of the fuse and get it out of there. The wire is a bit hard ( definitely harder than all the other wires ) which is something I've seen when wires get hot like that, they can become brittle. These wires, while a little stiff at the plastic, appear to be in tact otherwise.

I'm wondering if that fuse could have been the issue ? Maybe it should have popped but didn't ? That circuit doesn't seem to be directly connected to the circuit with the fusible link, but it is through the voltage regulator. I think the red wire from the voltage regulator is actually TO the voltage regulator for when the lights are turned on .. then that causes the regulator to put more amps back to the battery ? Is that right ?

I'm not quite sure here ..

 

[85Hokie]

your diagram is rather small and hard to read.....that 14 amp fuse.....SHOULD be a 15 amp fuse, no such thing as 14 amp (might have been a typo) that fuse IF it crumbled could be part of the problem as you mentioned. A poor connection can make you pull your hair out!

Here is a little larger map of the electrical ....

as for the "red" wire - somewhere there is a short to get that fusible link to get hot.
Replace the entire 15 amp that crumbled with a new one :

https://www.ebay.com/itm/5X-30A-6V-...lade-Type-Fuse-Holder-Fuse-O9C7-/173077219369

remove the 30 amp fuse and replace it with a 15 amp one (for the 15 amp that crumbled). To do this right, place shrinkwrap on the wires, solder them and then shrinkwrap them.

check all connections carefully.......you have the lights off, flashers off etc?

and hit the key again - worse case, the fusible link will blow and you will be back to square one.

 

[squarethumps]

The fuse that is in there has BUSS SFE 14 stamped on the metal end. Not a 14 amp fuse ?

I wasn't sure what the amperage tolerance of the fusible link was to know what to replace it with. 30 amp is ok then ? I think the local auto parts store has those kind.

Isnt soldering and shrink tubing the only way to do low voltage electric ? That's the way I always do them.

I will do and report.... I will probably unwrap the rest of that harness just to have a look. It's only another 10 inches. If the wires are good I'll see what happens after replacing the fuses.

Thanks for the response. Much appreciated.

 

[85Hokie]

as for the fusible link......not sure if 30 amp will do, looking at the diagram a little closer.....that is a 200 AMPS FUSE! and you are right - that 14 amp fuse, looking that up - there is a direct replacement for that! However the "diagram" shows no 14 amp, rather a 10 and 15 amp fuse.

https://www.amazon.com/Bussmann-BP-SFE-14-Acting-Glass/dp/B000BXMDW4

 

[squarethumps]

How can you tell it is a 200amp fusible link ?

I don't see that written anywhere?

 

[kubotasam]

I had it running fine the one day, and then I shut it off for a while and tried to start it again. In order to start the tractor, I have to use the glow plugs every single time, even if the tractor has only been off for 10 minutes. Anyway I was using the glow plugs and all of a sudden the glow plugs indicator started glowing brighter than ever .. like almost white ..it seemed like Sparks were coming from behind the indicator

Sounds to me like you have a short in the wire going from the glow plug indicator to the glow plugs. It turned white hot because it was of the large amount of current going through it.

 

[85Hokie]

How can you tell it is a 200amp fusible link ?

I don't see that written anywhere?

It is in your owners manual - pdf

page 13 ......

 

[rbargeron]

.......I think that if I were to replace that fusible link, the same thing would happen with the new one..........I'm just not quite sure what to test or change out.......

A new fusible link (around $7) would likely solve it. The wire crimps inside the plug get corroded with age and sometimes they smoke, most often they just stop conducting enough to work. A new one is the answer.

The link is designed to carry just enough current to run the starting solenoid, instruments, etc. but with very little extra capacity. It's supposed to burn out if current goes too high, protecting everything from a short circuit. Yours is near failing open and should be replaced.

 

[JerryMT]

I'm having an issue with my B8200 ( clutch, D950 ).

When I try and start the tractor, the fusible link starts to get hot and smoke. ( I stop before it burnt out completely )

I think that if I were to replace that fusible link, the same thing would happen with the new one.

The question is : The fusible link seems to protect everything on that side ( the key switch and everything it is connected to ) so how can I figure out what the REAL problem is ? I've replaced the key switch already because I thought it was bad, but I'm still getting the same symptoms.

At first, I was receiving 12v at the key switch through the red wire, and then, when I would simply turn the key to the RUN position, the voltage on that wire would disappear. I cleaned up the battery ground to the rear axle, and then I cleaned up the starter solenoid nut and ends that both attach there ( the battery positive cable, and the red wire which carries power to the ignition switch ). After doing that, I am now getting power to the key switch when I turn the key to the "RUN" position. But now ( as I said ) when I try to start it, the fusible link gets hot and starts to shoot smoke out of a hole it has burned for itself in the link wire cover. ( The starter does not turn over at all like this ... I've tested and jumped 12v directly to the starter itself and it will turn the engine over ).

Is there something on one side or the other that would be causing this ? The starter solenoid ? The voltage regulator ? Is it simply a bad fusible link that needs replaced ?

I'm just not quite sure what to test or change out.

Many many Thanks.

There is a short most likely between the battery and the starter solenoid . It could be the cable or the starter solenoid itself,(if you have that kind of starter) or in the magnetic switch if you have that kind of starter. if you hook it up directly, battery to starter, and the starter rolls over then it's got to be the other part of the circuit.

 

[North Idaho Wolfman]

It is in your owners manual - pdf

page 13 ......

Can you say typo!

I know what the manual says, But it's wrong.
That fusible link is 40 amp max.
There is no way a #10 wire would withstand 200 amps.

Take the feed wire from the starter solenoid (wire with the fusible link) to the switch off at the switch, measure voltage, if it's ~12V then that section should be good.
Touch that to the switch terminal that it goes to, if it sparks a lot you have something connected to the wrong terminals of the switch, If it does not then the short is most likely after the switch and could be in the Glow plug loop (and yes the glow plug loop gets power on glow position and on start position but not in the on position.

 

[Dave_eng]

I'm having an issue with my B8200 ( clutch, D950 ).

When I try and start the tractor, the fusible link starts to get hot and smoke. ( I stop before it burnt out completely )

I think that if I were to replace that fusible link, the same thing would happen with the new one.

The question is : The fusible link seems to protect everything on that side ( the key switch and everything it is connected to ) so how can I figure out what the REAL problem is ? I've replaced the key switch already because I thought it was bad, but I'm still getting the same symptoms.

At first, I was receiving 12v at the key switch through the red wire, and then, when I would simply turn the key to the RUN position, the voltage on that wire would disappear. I cleaned up the battery ground to the rear axle, and then I cleaned up the starter solenoid nut and ends that both attach there ( the battery positive cable, and the red wire which carries power to the ignition switch ). After doing that, I am now getting power to the key switch when I turn the key to the "RUN" position. But now ( as I said ) when I try to start it, the fusible link gets hot and starts to shoot smoke out of a hole it has burned for itself in the link wire cover. ( The starter does not turn over at all like this ... I've tested and jumped 12v directly to the starter itself and it will turn the engine over ).

Is there something on one side or the other that would be causing this ? The starter solenoid ? The voltage regulator ? Is it simply a bad fusible link that needs replaced ?

I'm just not quite sure what to test or change out.

Many many Thanks.

A short time ago a different forum member posted with the same problem. In the end it turned out his ground connection between the battery and engine block was corroded. The current flowing from the battery + to the starter did not have a good return path and started using the circuit with the fusible link which eventually ends at ground as the current flows through light bulbs etc.

It would be a good idea to run a battery type ground wire from the point of attachment of the battery ground on the rear axle to the starter mounting bolts. Buy a cable with an eye on each end. Available in different lengths.

If you have smoke coming out the insulation of the fusible link then your fusible link is blown. Its insulation is designed to stay in play and keep bare open wire ends from shorting and causing a fire.

There are tests which you could do to solve the problem but adding the additional ground cable is less work and is good insurance for the future.

Denso has an excellent diagnostic booklet at this link that shows you how to be checking for voltage drops in the starter electrical system.

http://densoautoparts.com/Portals/D...s/file/DENSO Starter troubleshooting tips.pdf

Dave

 

[squarethumps]

ADMIN - I had replied to all of this in a post just now and it said I wasn't logged in and deleted my post I wrote - I WAS logged in -- why did it do this ?

Take 2 :

A short time ago a different forum member posted with the same problem. In the end it turned out his ground connection between the battery and engine block was corroded. The current flowing from the battery + to the starter did not have a good return path and started using the circuit with the fusible link which eventually ends at ground as the current flows through light bulbs etc.

Initially I did have trouble with that ground connection at the axle, as when I would try to start the tractor, a spot on the bolt and connector would glow. I cleaned it all up and snugged it down tight. There may have already been damage to the fusible link at that point.

It would be a good idea to run a battery type ground wire from the point of attachment of the battery ground on the rear axle to the starter mounting bolts. Buy a cable with an eye on each end. Available in different lengths.

This was recommended by 2 people, so it must be a good idea !

If you have smoke coming out the insulation of the fusible link then your fusible link is blown. Its insulation is designed to stay in play and keep bare open wire ends from shorting and causing a fire.

There are tests which you could do to solve the problem but adding the additional ground cable is less work and is good insurance for the future.

Denso has an excellent diagnostic booklet at this link that shows you how to be checking for voltage drops in the starter electrical system.

Thanks for this information !

Can you say typo!

I know what the manual says, But it's wrong.
That fusible link is 40 amp max.
There is no way a #10 wire would withstand 200 amps.

This makes sense. I couldn't imagine where it would even get 200 amps ?

Take the feed wire from the starter solenoid (wire with the fusible link) to the switch off at the switch, measure voltage, if it's ~12V then that section should be good.
Touch that to the switch terminal that it goes to, if it sparks a lot you have something connected to the wrong terminals of the switch, If it does not then the short is most likely after the switch and could be in the Glow plug loop (and yes the glow plug loop gets power on glow position and on start position but not in the on position.

This is what I was doing .. the testing of that 12v at that key switch. It was inconsistently on and off, and seemed to do that when I was moving the wire bundle back and forth. I thought it was a problem at the starter stud so I cleaned up both the ends at that terminal ( the battery + wire end and the red wire that goes to the key switch end ). That initially seemed to take care of the inconsistent voltage at the key switch, but it came back, so I cleaned up the connector under the gas tank and that's when I found that problem with the 14 amp ( supposed to be 15 amp ) fuse. I think I said though, that wire is not directly connected to the red wire ( with fusible link ), except through the voltage regulator.

OK !! Very interesting to know that the glow plugs work in the START position as well ! All the wires in the glow plug loop from key switch to glow plugs to the indicator wires all seem to be good, no melted or bare spots.

There is a short most likely between the battery and the starter solenoid . It could be the cable or the starter solenoid itself,(if you have that kind of starter) or in the magnetic switch if you have that kind of starter. if you hook it up directly, battery to starter, and the starter rolls over then it's got to be the other part of the circuit.

I have used a wire directly from the + battery side directly to the actual starter ( not the solenoid ) and the starter will turn over the motor. Does this mean that the solenoid is good ? I did not take the 12v wire and put it to that solenoid blade ( yet ).. perhaps I should ?

A new fusible link (around $7) would likely solve it. The wire crimps inside the plug get corroded with age and sometimes they smoke, most often they just stop conducting enough to work. A new one is the answer.

The link is designed to carry just enough current to run the starting solenoid, instruments, etc. but with very little extra capacity. It's supposed to burn out if current goes too high, protecting everything from a short circuit. Yours is near failing open and should be replaced.

I bought 2 of them just in case I fried one.

I am going to put the new fusible link in, solder in an entirely new 15 amp blade fuse where the old 15 amp tube fuse was, and double check all the wiring for melted spots.
I also bought a new flasher ( hazard lights ) switch, which I will install. Then I will test and see what happens.

However, I currently have the hydraulic direcional block off as I was not getting any pressure in the loader. I'm not sure what's up there, except that my fluid is yellow milky with water ( must be water ? ) I don't know how it's getting in there because I've just recently changed it and the old fluid was the same - milky. I've replace the shifter boot ( mine was cracked ) and filled it full of grease before I clamped it in place. Then I started looking at the brakes ( since the right brake all of a sudden stopped working on me ) and I see that there is a lot of rust and moisture inside the brake drum housing. I have that all apart -- EXCEPT I can't get the brake drum out to change the seal that's behind that. If you want to respond to that topic :
http://www.orangetractortalks.com/forums/showthread.php?t=32305&highlight=brake+drum

So I have to put that system back together before I can try and start the tractor anyway.

 

[North Idaho Wolfman]

ADMIN - I had replied to all of this in a post just now and it said I wasn't logged in and deleted my post I wrote - I WAS logged in -- why did it do this ?

Because you took too long to write it, it's a safety feature.
Break your replies up to individual replies not a big group reply.
I've tried to read what you wrote and it's baffling when it doesn't list who made the quote.

 

[squarethumps]

OK, I will try to be more concise.

It seems as though I'm back to square 1. I put a new fusible link, and there is still something screwy, as my glow plug indication got white hot immediately when I tried to use the glow plugs, and the indicator itself burned out. The new one should be here in 10 days. ( I hate waiting ). I also ordered new glow plugs. Over the next 10 days I will unwrap all the wiring and examine it for shorts. The 1 wire that goes to the glow plugs appears to be in tact ( someone suspected a short here ).

I'll keep you all posted.

Thanks

 

[North Idaho Wolfman]

You have either a shorted glow plug or shorted wiring going to the glow plugs.

 

[85Hokie]

OK, I will try to be more concise.

It seems as though I'm back to square 1. I put a new fusible link, and there is still something screwy, as my glow plug indication got white hot immediately when I tried to use the glow plugs, and the indicator itself burned out. The new one should be here in 10 days. ( I hate waiting ). I also ordered new glow plugs. Over the next 10 days I will unwrap all the wiring and examine it for shorts. The 1 wire that goes to the glow plugs appears to be in tact ( someone suspected a short here ).

I'll keep you all posted.

Thanks

I typed up a response, then erased it.............

Wolfman said it better than I thought it............

to say what has been said, to get the fusible link to get hot, says one thing electrically..........amps are flowing and a lot of them!!!

A short to ground will do it quick like and in a hurry! And a reduction in OHMS will do it too (almost the same as a short), if anything in the glow plug circuit is shorted, it will flow too many amps also.

You moved the wire bundle ..... and something happened...........I would isolate all those wires and look at each one carefully to see if anything is shorting to ground.

AND as mentioned - you can have a dozen grounds.......electrons dont care which - as long as the circuit is clean and closed, them little buggers will flow!

Report back please

 

[Dave_eng]

OK, I will try to be more concise.

It seems as though I'm back to square 1. I put a new fusible link, and there is still something screwy, as my glow plug indication got white hot immediately when I tried to use the glow plugs, and the indicator itself burned out. The new one should be here in 10 days. ( I hate waiting ). I also ordered new glow plugs. Over the next 10 days I will unwrap all the wiring and examine it for shorts. The 1 wire that goes to the glow plugs appears to be in tact ( someone suspected a short here ).

I'll keep you all posted.

Thanks

When I try and study your wiring diagram, it comes up too small to really study. Perhaps someone can explain how to have a larger image appear or you provide a link to where you found it in the first place.

Your glow indicator glowing white and burning out is a clue something is wired incorrectly. Likely at the ignition switch.

Can you plse provide pictures of the glow plug side of your engine, the starter and the battery and the back of the ignition switch.

Has the ignition or key switch ever been changed, the glow plug indicator and wiring ever changed?

What is the history of your machine, what year, # of hours, Did you buy it new or used

You might consider using a marine style fuse block. The advantage of the "Marine" is that the connections to the fuse block are screw type which require an eye terminal end. On some Kubota's the original wires already have eye ends.

https://www.bluesea.com/products/category/16/61/Fuse_Blocks/ST_Blade
Dave