Could really use some help with finding problem with L3400 Kobota. As a new member

[LD1]

They very well could if there is a bad ground.

Unlikely in my experience.

Bad ground USUALLY results in stuff either working or not. Low amperage loads like lights, gauges, etc work. As there is "enough" connection to pass current.

Try to pass alot of current (like trying to start), and everything suddenly goes out.

"Dim" lights are usually a weak battery.

But a simple $20 meter would do wonders

 

[k0ua]

Get a multi-meter and learn how to use it

Best post of the day. Don't get me started on the failure of our schools to teach even a modicum of practical electrical skills.
I can go for hours on that subject.

 

[Egon]

Give boosting a try with the battery disconnected.

 

[/pine]

There are a lot of issues that appear to be electrical but are actually mechanical...a multi meter is not going to fix anything but they may or may not help guide you to the problem...
learning to use a meter is not the same as understanding automotive electrical systems...

 

[newbury]

Get the battery load tested several times.
I had one that showed a full charge with a mulitmeter but wouldn't kick the starter.
Took it to NAPA, they had a load tester. Tested it once, it passed, tested it a second time it failed. Replaced the battery, it's been starting for years.

 

[k0ua]

Get the battery load tested several times.
I had one that showed a full charge with a mulitmeter but wouldn't kick the starter.
Took it to NAPA, they had a load tester. Tested it once, it passed, tested it a second time it failed. Replaced the battery, it's been starting for years.

Yes, and a simple test with a multimeter with an assistant attempting to start the engine would have easily found that problem in seconds. A battery with a high internal resistance will show good voltage without load and will have a severe voltage drop under an attempted load. These types of tests take seconds to perform instead of getting out wrenches and taking batteries in for load testing. You have a perfectly good load tester at hand. It is called a tractor.

It is not enough though to have a multimeter, one must have an understanding of ohm's law and relationship of voltage, current and resistance in DC automotive circuits. I would love to teach the class!.

 

[sdquick]

Yes, and a simple test with a multimeter with an assistant attempting to start the engine would have easily found that problem in seconds. A battery with a high internal resistance will show good voltage without load and will have a severe voltage drop under an attempted load. These types of tests take seconds to perform instead of getting out wrenches and taking batteries in for load testing. You have a perfectly good load tester at hand. It is called a tractor.

It is not enough though to have a multimeter, one must have an understanding of ohm's law and relationship of voltage, current and resistance in DC automotive circuits. I would love to teach the class!.

I would love to read a long post or series of posts from you. Would be helpful to many of us that come hear to learn...

 

[Fallon]

Agree.....these dont really go together



Get a multi-meter and learn how to use it

I'd agree with the multimeter but in general. But in this case, check the grounds & battery cables first.

Had my L3200 dash torn apart troubleshooting with a multimeter. Battery ground cables looked great & were tight. Finally took a socket to the clean tight bolt holding the ground cable to the frame... the second I started loosening the bolt my emergency flashers started to work. Pulled the bolt & everything looked good. No corrosion, paint or what not & it had been tight. But that bolt was the cause of my pain. I was smarter than everybody else so I started troubleshooting under the dash with a multimeter as the cables they said to check were good looking. Not so smart after all.

 

[AndyMA]

I'd agree with the multimeter but in general. But in this case, check the grounds & battery cables first.

Had my L3200 dash torn apart troubleshooting with a multimeter. Battery ground cables looked great & were tight. Finally took a socket to the clean tight bolt holding the ground cable to the frame... the second I started loosening the bolt my emergency flashers started to work. Pulled the bolt & everything looked good. No corrosion, paint or what not & it had been tight. But that bolt was the cause of my pain. I was smarter than everybody else so I started troubleshooting under the dash with a multimeter as the cables they said to check were good looking. Not so smart after all.

Personally using a Multimeter set to DC voltage I would measure from teh actual battery post to a solid frame ground. Should be zero volts. Attempt to start or turn on as heavy load as possible. If it gets much larger than zero you have a high resistance int he ground path from the battery post to frame , Cable and or connections.

Andy
Electrical Engineer

 

[JWR]

First things first.
1) By far the simplest/easiest -- Use a jumper cable direct to the cable ends at the battery terminals only (not someplace else on the tractor.) You said it would not start. If it starts "readily" and "normally" using jumper cables to an external good battery then your battery is bad. Before replacing it , it is worthwhile to take it out of the machine, recharge it with a battery charger and then have a load test run on it. Potentially you have a bad charging circuit (and if the battery takes the charge and passes the load test that is likely.)
2) If the jumper cable route does NOT turn the engine then your most likely issue is the ground cable between the battery and the frame of the tractor. As others said -- clean and tighten all connections. Then retry with the jumper cables.

Forget the meters and other complexities until you've done 1) and 2) and know whether your battery is usable or not and whether you have a good ground connection.
By the way -- small Kubotas like the BX are a little bit notorious for losing ground quality over time. I do not know if that issue extends to the L3400 sizes or not.