B7610 Electrical Issue - dash lights won't come on and won't start

[RickDeShon]

Hi All. I have one of the hard to track down electrical problems. Tried to start the tractor, the dash lights came on, then I heard a soft electrical fizzle and the dash lights slowly died out to nothing. After that, nothing. No dash lights, no cranking. I've had the battery tested and it's good. I've cleaned all the battery connections all around. Battery wires feel good and show good continuity. I've checked voltage at the starter and it's getting 12v.

I've pulled all the fuses and tested for continuity. All fuses tested good. I've looked all over the tractor for lose wires and don't see any issues.

I've examined the safety switches and all appear to be in good working condition. I haven't jumped them yet to eliminate each one but I don't think the safety switches are the likely problem. Usually when I have a safety switch issue (usually the PTO lever out of neutral), the dash lights come on but the engine won't crank.

What's my next step? Pull the cowl off and examine the wires at the switch? Or what?

Thanks for your advice and let me know if there are any other test conditions I should check and share.

Best,

Rick

 

[PoTreeBoy]

Sounds like a classical short. There may be a fusible link or largeish master fuse up near the starter. Look carefully for burnt insulation or a black mark at the short. Don't be tempted to put a larger wire or fuse at the master fuse or you'll have bigger problems.

 

[Dave_eng]

Find and check for a slow blow fuse. It will be a 30 amp green one and located close to where the battery cable meets the starter motor.
If it is blown there has to be a reason way and your story may have earlier chapters such as the connection of booster cables or a battery charger with cables reversed.
If it is blown and none of my suspected previous events happened, before installing the new slow blow fuse, check all lower amp fuses.
There has to be a reason.......

Dave

 

[GreensvilleJay]

re: I heard a soft electrical fizzle and the dash lights slowly died out and all fuse good...

sounds like the main fuse ( a fusible link ) has opened(blown) due to a short to ground after it BUT BEFORE the main fuse panel. If it'd been after, then a fuse in the fuse panel would have blown.
A wiring diagram would really help, best to see if there's a WSM at Kubotabooks.com.

 

[RickDeShon]

Sounds like a classical short. There may be a fusible link or largeish master fuse up near the starter. Look carefully for burnt insulation or a black mark at the short. Don't be tempted to put a larger wire or fuse at the master fuse or you'll have bigger problems.

Thank you! I've pulled the 30amp measter fuse near the starter and it looks good and continuity tests good. I don't see any evidence of burning or shorting in the area of any of the fuses.

 

[RickDeShon]

Find and check for a slow blow fuse. It will be a 30 amp green one and located close to where the battery cable meets the starter motor.
If it is blown there has to be a reason way and your story may have earlier chapters such as the connection of booster cables or a battery charger with cables reversed.
If it is blown and none of my suspected previous events happened, before installing the new slow blow fuse, check all lower amp fuses.
There has to be a reason.......

Dave

Thanks! All the fuses including the master 30amp fuse (mine is red, not green) continuity test good. Maybe I'll just get a new fuse and try to replace it anyway?

 

[PoTreeBoy]

Thank you! I've pulled the 30amp measter fuse near the starter and it looks good and continuity tests good. I don't see any evidence of burning or shorting in the area of any of the fuses.

A wire could have burnt in two. The fuse boxes are somewhat prone to lose connection.

 

[RickDeShon]

A wire could have burnt in two. The fuse boxes are somewhat prone to lose connection.

Thanks PoTreeBoy. Any thoughts on how to track down a wire that broke or burnt in two? Should I pull apart the harness and just start going through one by one or is there a better strategy?

 

[GreensvilleJay]

start at battery with DVM, confirm battery has 12V
move red probe to the red fusible link, confirm 12v coming OUT of it
move red probe to fuse block, yes all the fuses with key off, some will have 12v,most not

it's the ' I heard a soft electrical fizzle and the dash lights slowly died out ' that seems to indicate an open wire if all the fuse show 'good'.

 

[TheOldHokie]

Thanks! All the fuses including the master 30amp fuse (mine is red, not green) continuity test good. Maybe I'll just get a new fuse and try to replace it anyway?

The usual procecedure is to use your multimeter to check voltages along the conductor. If the main fuse is good you will show battery voltage on the load side of the fuse. Then you move up to the fuse box and check the feed there. Repeat until fault is found.

Dan

 

[GreensvilleJay]

it'd be nice to have wiring diagrams stored 'somewhere' on this forum....
...it'd help some of us help others trouble shoot their 'electrical gremlins'.

 

[RickDeShon]

Thanks Dan and GreensvilleJay. I'll try that testing process tomorrow and report back.

 

[Dave_eng]

it'd be nice to have wiring diagrams stored 'somewhere' on this forum....
...it'd help some of us help others trouble shoot their 'electrical gremlins'.

Here is wiring diagram.
Post some photos of top of battery and where ground cable connects to chassis.
A poor connection can produce a sound like you describe when it is asked to conduct high current like starting.
Dave

 

[RickDeShon]

Excellent. Thanks Dave!

 

[RickDeShon]

Hi All. Okay, an interesting development. I took the battery out to charge it last night just in case.

Installed it today to get the pics Dave requested. Turned the key and the dash lights came on and the glow plugs started doing their thing. Waited about 8 seconds and then depressed the clutch to start it. Heard a click after depressing the clutch and the dash lights went out and everything is dead again. If I try to turn the key again the dash lights are completely dead. So this seems interesting and potentially diagnostic. Any ideas? Here's a pic of the battery and grounding connection

 

[RickDeShon]

Got it! This is embarrassing but it was the battery connection after all. I cleaned the positive terminal connector but I didn't think to clean the cable connection to the terminal...under the red cover in the picture above. Took it apart and found it well rusted. A bit of emory cloth, reconnected, and fired right up.

I had 12 volts to the starter so I assumed I had a good enough positive connection. A good lesson that 12v down line doesn't mean you don't have problems with the battery connection.

Thanks everyone for your help!

Rick

 

[GreensvilleJay]

Please get RID of that battery cable PDQ. Buy a good quality molded one.
Actually I'd replace them BOTH,now.

 

[RickDeShon]

Please get RID of that battery cable PDQ. Buy a good quality molded one.
Actually I'd replace them BOTH,now.

Good advise. The negative cable is OEM. But I will replace both.