Slow blow fuse, battery replaced

Robert kubota 7500

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Equipment
Kubota b7500
Nov 22, 2022
9
2
3
Beaumont ca
I changed a dead battery and ran into problems afterward. Initially tried to start, and nothing happened except a single click type of sound. Tried again and this time the starter motor spun with no engine turn over. Tried a third time and nothing happened. Slow blow fuse is blown. Put a new fuse in but it immediately blew as I inserted it.
 

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GreensvilleJay

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BX23-S
Apr 2, 2019
5,699
2,033
113
Greensville,Ontario,Canada
The fuse blowing while being inserted means there IS a 'short' somewhere.
Would need to see the wiring diagram to help locate it. probably will be BEFORE the fuse block as the slow blow fuse blew, not any of the little ones.

BTW, I'd replace BOTH battery cables, the +ve one looks corroded and the -ve is a 'squeezy' type,which will corrode fairly fast. I'd use heavier gauge premade cables.
 
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Robert kubota 7500

New member

Equipment
Kubota b7500
Nov 22, 2022
9
2
3
Beaumont ca
The fuse blowing while being inserted means there IS a 'short' somewhere.
Would need to see the wiring diagram to help locate it. probably will be BEFORE the fuse block as the slow blow fuse blew, not any of the little ones.

BTW, I'd replace BOTH battery cables, the +ve one looks corroded and the -ve is a 'squeezy' type,which will corrode fairly fast. I'd use heavier gauge premade cables.
Seems strange since I haven't messed with any thing else to have created a short. Any idea why the starter engaged with no engine turnover prior to the fuse blowing?
 

Dustyx2

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BX22, M7060, Landpride RC-2512, Woodmax SB84
Feb 19, 2021
156
37
28
NE Wyoming
Are you sure you have the cables correct? The black cable you have on the negative post looks to run into a loom which seems odd for a ground cable. I'd make sure your positive cable is running to the starter.
 
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DustyRusty

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BX23S
Nov 8, 2015
2,774
1,806
113
North East
The black cable is going to the starter yep. Hope I didn't mess anything up besides the fuse
Take another look at his picture. Do you see the + above the red battery cable terminal? The battery is correctly installed. He could have pinched a wire installing the battery and that wire is now grounding, causing the blown fuse. I also do not care for the cheater terminal on the negative terminal, since the entire cable could have corrosion under the covering. Most likely the reason that the terminal was replaced as it was corroded badly and not serviceable. I can see evidence of corrosion on the positive terminal also, so I would replace them both to guarantee reliable service from the battery going forward.


20221122_135105.jpg
 
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Dustyx2

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Equipment
BX22, M7060, Landpride RC-2512, Woodmax SB84
Feb 19, 2021
156
37
28
NE Wyoming
Take another look at his picture. Do you see the + above the red battery cable terminal? The battery is correctly installed. He could have pinched a wire installing the battery and that wire is now grounding, causing the blown fuse. I also do not care for the cheater terminal on the negative terminal, since the entire cable could have corrosion under the covering. Most likely the reason that the terminal was replaced as it was corroded badly and not serviceable. I can see evidence of corrosion on the positive terminal also, so I would replace them both to guarantee reliable service from the battery going forward.


View attachment 91078
He says the black cable is going to the starter so it is not hooked up correctly in the picture. Colors apparently weren't important to whoever replaced the cables in the past.
 

DustyRusty

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Equipment
BX23S
Nov 8, 2015
2,774
1,806
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North East
He says the black cable is going to the starter so it is not hooked up correctly in the picture.
I know what he said, but I also know that the red cable is the positive cable. Now, if someone replaced the cables and wired them incorrectly without regard to the color of the cables, then I could agree with you. I am inclined to believe that he might not have all the facts correctly. This is the problem with not being there to check the accuracy of the description of what goes where. All that I can go on is what is visually presented and the industry norms of color coding to avoid mistakes. If the battery cables were reversed, that wouldn't cause the fuse to blow. It would blow out the diodes in the alternator, and possibly do some other damage, but fuses are not positive or negative proprietary. They are designed to protect the wiring during an over-current situation.
 
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Dustyx2

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Equipment
BX22, M7060, Landpride RC-2512, Woodmax SB84
Feb 19, 2021
156
37
28
NE Wyoming
I know what he said, but I also know that the red cable is the positive cable. Now, if someone replaced the cables and wired them incorrectly without regard to the color of the cables, then I could agree with you. I am inclined to believe that he might not have all the facts correctly. This is the problem with not being there to check the accuracy of the description of what goes where. All that I can go on is what is visually presented and the industry norms of color coding to avoid mistakes. If the battery cables were reversed, that wouldn't cause the fuse to blow. It would blow out the diodes in the alternator, and possibly do some other damage, but fuses are not positive or negative proprietary. They are designed to protect the wiring during an over-current situation.
I would agree that reverse polarity doesn't explain the blown fuse but I do believe the red cable is likely the ground cable, and shame on whoever did that. The OP will have to let us know what he finds. I do think he needs to see where the red cable goes. I'm betting the frame.
 

lugbolt

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ZG127S-54
Oct 15, 2015
4,148
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Mid, South, USA
reversing the battery cords can pop the slow-blow. I've done it. Several times. Usually on equipment that's had the cords replaced with both black or both red or speaker wire or whatever they used.

kubota calls em earth cord (ground) and plus cord (positive). I guess that's the jinglish terms.

when i worked at the dealer and needed a positive cable, I'd write "earth cord" on the R/O and send it to parts. The new guy would scratch his head for an hour or two trying to find an earth cord in the breakdowns.
 
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Robert kubota 7500

New member

Equipment
Kubota b7500
Nov 22, 2022
9
2
3
Beaumont ca
I would agree that reverse polarity doesn't explain the blown fuse but I do believe the red cable is likely the ground cable, and shame on whoever did that. The OP will have to let us know what he finds. I do think he needs to see where the red cable goes. I'm betting the frame.
Red cable is bolted to chassis it turns out... go figure. Reversed cables and tractor starts. Black cable runs to starter. Will need to check the alternator for damage. Thanks everyone. I will redo these cables going forward.
 
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ve9aa

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tg1860, bx2380
Apr 11, 2021
651
421
63
NB, Canada
Do yourself a favour. AT THE VERY LEAST,(before next time) buy some red and black colored/coloured electrical tape and "make" the cables the right color/colour at least until you can replace them with the CORRECT ones.
 
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GreensvilleJay

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Equipment
BX23-S
Apr 2, 2019
5,699
2,033
113
Greensville,Ontario,Canada
hmm... I'm thinking the new battery has the + and - post REVERSED from the old,dead battery.
That would easily explain the 'poof' problem.
I KNOW first hand that U1 and U1R batteries for riders can cause the starter to go in reverse !
I've also got a couple 'car' batteries on the shelf that are 'funny'......
 

GeoHorn

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M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
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Texas
Reversed polarity is one of the purposes of the fuse….to “blow” in order to prevent addt’l damage. Says so in my OM.

Also…tho’ I’ve never experienced it…. I‘ve read in These Forums that a battery polarity can be reversed if improperly charged.