I have a B7500 that will not start on it's own. It has 900 hours on the engine. The battery that I had was a Kubota battery, only two years old with a five year warranty. Over the course of the summer and fall when I tried to start the tractor it would turn over once or twice and that was it. I would use a battery jump pack and it would turn over a few more times but wouldn't start. All lights on the gauge would light up but I thought the battery must have a bad cell and not enough cranking power and it was dead. I would jump start it with my truck and I would be good to go until I turned the engine off. I replaced the alternator four years ago and an alternator test when the engine is running shows it is good. For the rest of the summer and fall i used my truck to jump start the tractor. I finally took the battery out to replace it but needed to use the tractor several times before I purchased a new battery. I would jump it from my running truck connected straight to the battery cables (but with no battery in the tractor) and use it with no issues. I finally purchased a new Kubota battery, installed it and it would turn over one or two times (like before) and wouldn't start. After one or two more attempts the lights on the dash, (power, start and glow plug light) would not come on. Same story with the battery jump pack, a couple more turns and that was it, then no lights. I go get my truck, jump it and it starts right up. I use the tractor for three hours, turn it off and it won't start again. Go get my truck, jump it and it's good to go. What am I missing? Seems like it thinks its turned into a EV and want's 24 volts to start now.
B7500 will only start when jumped by running truck
- Thread starter mowxman
- Start date
I assume both battery posts/terminals are clean. Sounds like a bad battery ground cable (is it the woven type) or where the ground connects to the engine needs cleaning. To prove, take one jumper cable and go from the negative on the battery and connect the other end to the starter mounting bolt.
Kubota Newbie
Active member
Equipment
M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
Well if you are connecting the cables correctly and the truck is a 12 volt system you still only have 12 volts. Since it's not sounding like a safety switch issue I would suspect a bad ground or other primary cable connection. Remove, clean and reinstall the ground cable/wires, and for good measure make sure the positive cable and wire connections on the starter/solenoid are clean and tight. It might just be the extra amperage you have when hooking up the truck is enough to overcome a poor connection somewhere.
Runs With Scissors
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L2501 TLB , Grappel, Brush Hog, Box Blade, Ballast box, Forks, Tiller, PH digger
Dont forget to check the entire length of both + and - cables for "internal corrosion"
I was working on an F-150 many years ago that would not turn over, but the dash lights still worked.
Long story short, the the positive battery cable looked like snake that just swallowed a mouse. It was filled with corrosion.
I was working on an F-150 many years ago that would not turn over, but the dash lights still worked.
Long story short, the the positive battery cable looked like snake that just swallowed a mouse. It was filled with corrosion.
Where are you hooking the jumper cables to the tractor?
If on the clamps at the battery posts sounds like you have a bad connection between one on the posts (or both) and the clamps. Remove both, clean the inside clamping surfaces well, and the posts too, replace and see what happens. Physically clean the them, not just a visual inspection.
If on the clamps at the battery posts sounds like you have a bad connection between one on the posts (or both) and the clamps. Remove both, clean the inside clamping surfaces well, and the posts too, replace and see what happens. Physically clean the them, not just a visual inspection.
ve9aa
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TG1860, BX2380 -backblade, bx2830 snowblower, fel, weight box,pallet forks,etc
The guys already nailed it.
Battery cables and connections to tractor.(ground, starter lug)
Battery cables and connections to tractor.(ground, starter lug)
But if he hooked his jumper cables to the clamps on the battery posts, then he basically verified all those things…if the engine started with no issues as reported.
Now if he jumped it to the positive terminal of the starter and to the starter case, that’s a completely different story and verifies nothing other than the Starter motor works.
Edit: Just to clarify one thing. If the jumper cables were connected to the starter directly, and not the battery post clamps, before trying to start, the positive voltage would be fed back to the original battery at a relatively low current level. So bad connections (that would drop a great amount of voltage when the high current was drawn when the starter was energized) would not be apparent when the starter solenoid was energized in the normal way, since most of the juice would be coming through the jumper cables, and not the OEM tractor cables.
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Always the best first step.
Unfortunately, some may not have a voltmeter, or even if they buy one, many not understand electrical principles well enough to accurately analyze what the readings mean overall.
So sometimes it is necessary to eliminate the problems in ways other than electrical analysis...