Hour meter problem

[Rosohatica]

Hi, I bought Kubota B1402, and the original hour meter was not running. Original one looked like this https://www.orangetractortalks.com/forums/attachments/image-jpg.39380/

I bought a new one

https://asset.conrad.com/media10/isa/160267/c1/-/hr/125691_LB_00_FB/image.jpg?x=400&y=400

And I installed it. Before installation I tried to connect it to the tractor battery directly and it ran OK. But when I connected it to its right place, it wouldnt work. The red LED worked same as when connected directly to the battery but the digits on the hour meter wouldn`t work. So I gauged how much DC output I get on the wires. And its only 3V, comparing to the 12V which I have from the battery directly. I guess 3V is enough to lit the LED lamp but not enough to get the digits running? What makes me think is - how did the original hour meter ran on only 3V, since it says 12 V on the casing of the original hour meter? Or is it some kind of malfunction of the tractor wiring? How did 9V got lost from the battery to the output? Whet can I do about it? Can I increase the output somehow or I need another hour meter which runs on 3V? Can someone help me on this please?

Best wishes

 

[Hammarhead]

The original meter probably was malfunctioning due to the same low voltage issue. There is probably an high resistance connection issue somewhere in the wiring causing your problem. Reference the wiring diagram and work backwards from the meter to the battery source until you locate where the voltage drops. Make sure to verify both the battery and ground paths as either can cause issues.

 

[GreensvilleJay]

simple test. Place DVM blk probe onto battery -ve terminal, use red to measure voltage at red wire of hr meter. IF you read +12, you have a ground return problem from hr meter to battery -ve. The 9 volts is 'lost' due to corrosion over the years....
If the grounding is good, then check the fuse and holder.Again ,corrosion over the years can build up .
Red LEDs only need 1.6 volts to light up.....
I found a B1400 wiring diagram online but not a B1402.....

 

[Flintknapper]

Hi, I bought Kubota B1402, and the original hour meter was not running. Original one looked like this https://www.orangetractortalks.com/forums/attachments/image-jpg.39380/

I bought a new one

https://asset.conrad.com/media10/isa/160267/c1/-/hr/125691_LB_00_FB/image.jpg?x=400&y=400

And I installed it. Before installation I tried to connect it to the tractor battery directly and it ran OK. But when I connected it to its right place, it wouldnt work. The red LED worked same as when connected directly to the battery but the digits on the hour meter wouldn`t work. So I gauged how much DC output I get on the wires. And its only 3V, comparing to the 12V which I have from the battery directly. I guess 3V is enough to lit the LED lamp but not enough to get the digits running? What makes me think is - how did the original hour meter ran on only 3V, since it says 12 V on the casing of the original hour meter? Or is it some kind of malfunction of the tractor wiring? How did 9V got lost from the battery to the output? Whet can I do about it? Can I increase the output somehow or I need another hour meter which runs on 3V? Can someone help me on this please?

Best wishes

Your new hour meter requires a minimum of 10vdc to operate and a maximum of 80vdc.

You'll need to find the source of your voltage loss in the circuit or the ground to it.

 

[Rosohatica]

simple test. Place DVM blk probe onto battery -ve terminal, use red to measure voltage at red wire of hr meter. IF you read +12, you have a ground return problem from hr meter to battery -ve. The 9 volts is 'lost' due to corrosion over the years....
If the grounding is good, then check the fuse and holder.Again ,corrosion over the years can build up .
Red LEDs only need 1.6 volts to light up.....
I found a B1400 wiring diagram online but not a B1402.....

Hi, thank you all for the tips. I think B1400 is more or less the same tractor as B1402 and at least wiring should be the same. I have found it as well but its a hard to see low quality copy.

 

[Rosohatica]

The original meter probably was malfunctioning due to the same low voltage issue. There is probably an high resistance connection issue somewhere in the wiring causing your problem. Reference the wiring diagram and work backwards from the meter to the battery source until you locate where the voltage drops. Make sure to verify both the battery and ground paths as either can cause issues.

Thanks, there is socket at the end of the hourmeter so it can be attached/dettached from the tractor wiring. I kept it and used it with the new hourmeter. It does look kind of yellowish inside so I think there might be a buildup of corrosion which causes 9V to be lost? Attached look at the picture please.

 

[Hammarhead]

Thanks, there is socket at the end of the hourmeter so it can be attached/dettached from the tractor wiring. I kept it and used it with the new hourmeter. It does look kind of yellowish inside so I think there might be a buildup of corrosion which causes 9V to be lost? Attached look at the picture please.

It's impossible to diagnose online if that yellowed connection is related to your issue or not. Clear plastic insulation sometimes yellows naturally with age so it may just be normal. You can check by taking a resistance reading between each side of the connection with a VOM and verify it is not a high resistance connection. Referencing the wiring diagram, any connection point is a good place to test on the tractor for a high resistance connection which will cause your voltage loss. Follow each leg of the circuit back from the meter to the point you find 12 volts and you should be able isolate the problem.

 

[Rosohatica]

It's impossible to diagnose online if that yellowed connection is related to your issue or not. Clear plastic insulation sometimes yellows naturally with age so it may just be normal. You can check by taking a resistance reading between each side of the connection with a VOM and verify it is not a high resistance connection. Referencing the wiring diagram, any connection point is a good place to test on the tractor for a high resistance connection which will cause your voltage loss. Follow each leg of the circuit back from the meter to the point you find 12 volts and you should be able isolate the problem.

Thanks, it took me awhile to find a wiring diagram. See it attached. I cant find hourmeter on that. Are you guys seeing it? If it helps, its wired with black/red and black/white wires. Thanks in advance.

 

[GreensvilleJay]

No hour meter in that wiring diagram. I did see another 'B1402 ' diagram that I've attached. Diffenert wire colours so maybe NOT really a B1402. It does show the 'ground' of the hour meter goes to the oil pressure switch. Makes sense.When engine is running, there's oil pressure, allows current to flow to meter to record RUNNING actual engine time. If this IS how yours is wired ,a 'bad' oil pressure switch can easily give 'funny' readings. If you can post a couple nice pictures of your dash and wiring. It seems like there's 2 versions of that tractor and the hr meter was added later. Lots of changes like dash hole, the mere, wiring, etc. so IF we could find a 'B1402 revision A' manual ,it may show the true wiring.
black/red sounds like +12, blk/wht the ground. Interesting colour choices..seeing how 'blk' can be both power or ground depending on where you live !

 

[Rosohatica]

No hour meter in that wiring diagram. I did see another 'B1402 ' diagram that I've attached. Diffenert wire colours so maybe NOT really a B1402. It does show the 'ground' of the hour meter goes to the oil pressure switch. Makes sense.When engine is running, there's oil pressure, allows current to flow to meter to record RUNNING actual engine time. If this IS how yours is wired ,a 'bad' oil pressure switch can easily give 'funny' readings. If you can post a couple nice pictures of your dash and wiring. It seems like there's 2 versions of that tractor and the hr meter was added later. Lots of changes like dash hole, the mere, wiring, etc. so IF we could find a 'B1402 revision A' manual ,it may show the true wiring.
black/red sounds like +12, blk/wht the ground. Interesting colour choices..seeing how 'blk' can be both power or ground depending on where you live !

Hi, thanks for the wiring and the comment. Currently I am not near the tractor so cant take a picture ( its at the weekend house), but taking photo of the wiring might be tricky. Most of it is under the hood so hard to see, let alone take a picture. But here is something that made me think today, when I was near it and it might have something to do with the oil pressure switch that you mention. I wrote earlier what colors are the wires that were attached to the original hour meter. Today I noticed third wire that wasn`t attached to hour meter but its nearby and lose . As if it was attached to something and is not anymore. Whats interesting is that it is of the same color as one of the wires attached to the hour meter. And its not cut lose. It has a small socket attached to it. But I don`t see what it might have been attached to originally. Just one loose end, not two.