2017 kubota bx25d - tachometer inoperable

[Illinifan]

Hi, I just purchased a bx25d and noticed the tach doesn't work. When I start the tractor the digital tachometer needle sweeps to high rpm then rests at 0 rpm and stays there. I have checked the fuses and they are good. From reading other posts apparently the tachometer operates from pulse from alternator signal. As many bx models in use I would think/hope others have experienced this too. I plan to test battery and alternator output tomorrow. Any help or advice is appreciated. Thanks

 

[frogpond]

On my bx25d, I had this exact symptom a couple months ago. It turned out that my fan belt was loose. Try tightening it. It's a little hard to get at the lower bolt on the alternator without taking off the engine housing, but it can be done. In my case, the belt was too stretched out to adjust any further, so I had to replace it. I hope you don't have to do that, as it's a pita. But the gauge problem was instantly solved. Also, of course, it should help the alternator and the fan to operate better.

 

[Illinifan]

Thanks Frogpond, I noticed the belt was loose yesterday but didn't think it was loose enough to cause that so you give me hope it will. I will post results after I get a chance to check it. I would much rather replace the belt than the alternator ($) if I have a choice.

 

[Illinifan]

Frogpond, I tighten the alt belt but unfortunately did not fix the tach. For some reason there is alot of oil residue on the alternator. This tractor is new to me so I'm unsure why. I confirmed the alternator is not charging the battery 12.34V with key off and actually 12.28V running. I would appreciate any diagnostic suggestions. Thanks

 

[Illinifan]

Fixed.Just wanted to provide update with resolution. There were 2 problems. I replaced the alternator with a genuine kubota alternator ($410 ouch) which fixed the charging problem but not the tachometer / hour meter. I crawled underneath tractor and found a broken red/yellow wire broken close to the connector to the fuel pump. I repaired wire and it fixed the the tach and hour meter. Hope it helps. Thanks.

 

[j13smiley]

That wire stopped the hour meter also? I assume you bought this used?

 

[Illinifan]

Yes, the hour meter and tach use the same wire.

 

[s2kskibum]

Curious - were you popping any fuses? I am dealing with a 10a fuse issue which kills all the idiot lights and the tach is behaving exactly as yours is. Thanks!

 

[Illinifan]

No, not popping fuses because it was an "open" with wire broken. Not sure If it blew a fuse when damage was done then fuse replaced later because I purchased it that way. You only blow a fuse when there is a short to ground in circuit before the current gets used by the load. You must have a short to ground on that fuse circuit. Good luck

 

[s2kskibum]

Thanks. Had it at a dealership, mechanic could not find anything wrong. I have no confidence in the mechanic. I'll look where yours was shorted, maybe that will be it!