kubota b2400 dynamo

   / kubota b2400 dynamo
  • Thread Starter
#11  
thanks. it appears that i might have a harness (i guess i'll need to pop the hood when it's light outside). from that diagram by dale (thanks very much BTW), i see the dynamo goes straight to the regulator, consisting of a wheatstone bridge. the charge lamp doesn't light up anymore (it did when i was running halogen lights), i remember trying to test the alternator, when i changed out my lighting, and i got 13v which seems low, but should be enough to charge. i wonder if the charge light has burned out. anyway, thanks. i'll tear into it this weekend and see what i can find.
 
   / kubota b2400 dynamo #12  
nfisheremti said:
thanks. it appears that i might have a harness (i guess i'll need to pop the hood when it's light outside). from that diagram by dale (thanks very much BTW), i see the dynamo goes straight to the regulator, consisting of a wheatstone bridge. the charge lamp doesn't light up anymore (it did when i was running halogen lights), i remember trying to test the alternator, when i changed out my lighting, and i got 13v which seems low, but should be enough to charge. i wonder if the charge light has burned out. anyway, thanks. i'll tear into it this weekend and see what i can find.
Click to expand...

Check the lamp some systems actually require a operating charge lamp to initiate the charge sequence of alternator systems but as you have a dynamo I suspect its a "generator" it may not need the lamp, but check it anyway... One never knows....

Functioning generator or alternator should top out about 13.8 to 14.2 volts... 12.5 to 13.5 volts is just battery float voltage, doe snot indicate charge..

And in regulator its a "full wave bridge rectifier" (by diagram) and not Wheatstone bridge....

Dale
 
   / kubota b2400 dynamo #13  
See your dealer for an alternator conversion kit about 200 bucks
Good Luck
 
   / kubota b2400 dynamo
  • Thread Starter
#14  
DL Meisen said:
Check the lamp some systems actually require a operating charge lamp to initiate the charge sequence of alternator systems but as you have a dynamo I suspect its a "generator" it may not need the lamp, but check it anyway... One never knows....

Functioning generator or alternator should top out about 13.8 to 14.2 volts... 12.5 to 13.5 volts is just battery float voltage, doe snot indicate charge..

And in regulator its a "full wave bridge rectifier" (by diagram) and not Wheatstone bridge....

Dale
Click to expand...

thanks dale, i stand corrected. obviously something is wrong. i'm pretty sure i've totally killed the battery at this point, and i'll need to replace that too. i was hoping to make it through the winter without having to replace anything expensive (i use the tractor with a 60" farm king snowblower on the back to clear about 20 driveways in my neighborhood), margins are tight (maintenance is my largest expense), and nighttime operation is a must.

sorry number 2, i'm balking at $165 for a straight replacement of the dynamo from kubota, and i'm wondering if i can get away with a $50 one off ebay or amazon, or something automotive from a junkie.
 
   / kubota b2400 dynamo #15  
Look around locally to see if you have a industrial/electrical repair facility that services fork lifts and diesel trucks and such ... They used to be around in many places before we became a "throw away' society....If you can find one remove "dynamo" and regulator and take it in to see if they can test it... Check phone book for "automotive electrical services"...

Did a real quick search at GOOGLE SHOPPING and this is what first came up....

https://www.dbelectrical.com/produc...iEbGJo7rul9RwACK0_3pcwsSW73BrcCRoCUMYQAvD_BwE

OR maybe..

NEW ALTERNATOR for CHEVY MINI DENSO STREET ROD 1-WIRE 35 AMP 4-5262 1218-SE | eBay

If your tractor is similar to mine, all it does is charge battery and run lights....Not to much electricals...

Also would put something like this in dash to monitor things

DC 12V-24V LED Panel Digital Voltage Volt Meter Display Voltmeter Motorcycle Car | eBay

Not endorsing any particular one, just to show you don't have to spend a ton of money....

Biggest issue may be modding brackets to make it fit....


Dale
 
Last edited:
   / kubota b2400 dynamo #16  
nfisheremti said:
thanks. it appears that i might have a harness (i guess i'll need to pop the hood when it's light outside). from that diagram by dale (thanks very much BTW), i see the dynamo goes straight to the regulator, consisting of a wheatstone bridge. the charge lamp doesn't light up anymore (it did when i was running halogen lights), i remember trying to test the alternator, when i changed out my lighting, and i got 13v which seems low, but should be enough to charge. i wonder if the charge light has burned out. anyway, thanks. i'll tear into it this weekend and see what i can find.
Click to expand...

Remember, what you have is a dynamo. Permanent magnets rotating around a coil(s) of wire. To test, you need to disconnect wiring at dynamo and measure alternating current voltage. It should be approx 40 volts between each pair of wires if your dynamo has 3 wires.

They are very simple and rarely fail. The rectifier/regulator is a different story as far as reliability is concerned. Rather than change the dynamo's output, the rectifier dumps excess current by converting it to heat. In the beginning, as you converted to LED lighting, you reduced the current draw by the tractor and require the rectifier to dump increased current and you may have cooked it.

Dave M7040
 
   / kubota b2400 dynamo
  • Thread Starter
#17  
interesting thought, but what was kubota thinking when they allow you to not turn any lights on? i would think the rectifier would be designed to dump all of that heat and then some. but certainly checking the voltage regulator is a good idea.

i would think if i disconnected the battery, jumped the tractor and measured the voltage to the battery leads, i should get the 13.8 to 14.2 that dale mentioned above. i suspect i won't but that would test the dynamo and the regulator at the same time. then if i pull the dynamo and bring it to someone to test, if that works, then i must be the regulator right?
 
   / kubota b2400 dynamo #18  
nfisheremti said:
interesting thought, but what was kubota thinking when they allow you to not turn any lights on? i would think the rectifier would be designed to dump all of that heat and then some. but certainly checking the voltage regulator is a good idea.

i would think if i disconnected the battery, jumped the tractor and measured the voltage to the battery leads, i should get the 13.8 to 14.2 that dale mentioned above. i suspect i won't but that would test the dynamo and the regulator at the same time. then if i pull the dynamo and bring it to someone to test, if that works, then i must be the regulator right?
Click to expand...

Test the dynamo. It is simple. If you do not have a multi meter, spend $10 on a cheap one and I will show you how to test the dynamo.
rPX0661.jpg

The dynamo is not something you fix as there are so few "fixable" parts unlike an alternator or generator. They rarely fail.

This test for the dynamo is from John Deere just because it is very easy to understand.

Connect voltmeter, set to read AC voltage, to alternator
outputs (B).
5. Start and run engine at fast idle. The meter should read
a minimum of 40 volts AC at FAST idle (3250 rpm).
Results:
• If reading is BELOW specification, test alternator.
Specifications:
Slow Idle (1400 RPM) . . . . . . . . . . . . . . . . . . . . . . .32 VAC
Fast Idle (3250 RPM) . . . . . . . . . . . . . . ..................50 VAC


Dave M7040
 
   / kubota b2400 dynamo
  • Thread Starter
#19  
i do have a meter. i'll give that a try. does anyone know what they are for a kubota b2400? i red line right around 3k. thanks.
 
   / kubota b2400 dynamo #20  
You must log in or register to reply here.
 

Footer Links 1

Top