Alternator Prices

In Utopia

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L175 FEL
Apr 21, 2013
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Present alt. on my L175 is just barely putting out 12v, so I go shopping for a replacement.
Why are prices ranging from $65 - $215 for what look like two different types.
Why is there such a big price spread?
Heck called a rebuild shop and they wanted around $100 for a rebuild.
 

200mph

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Are you certain you have an alternator and not a dynamo? The dynamo’s rarely go bad but the voltage regulator does. Dynamos have an AC output on the two wires and will change a bit with rpm.
 

100 td

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I would expect if you explore alternator replacement you may be able to get something new for your lower price you have mentioned, what is wrong with yours? Have you checked brushes, connections, regulator/ground connections?
 

In Utopia

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L175 FEL
Apr 21, 2013
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It 's an alternator. Has 3 pin connector on the rear.
Check all the connections, same thing, 12.8 volts max, don't know how many amps.
Not about to take it apart just to check it out.
Just wondering why the big difference in prices.
 

Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
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It 's an alternator. Has 3 pin connector on the rear.
Check all the connections, same thing, 12.8 volts max, don't know how many amps.
Not about to take it apart just to check it out.
Just wondering why the big difference in prices.
Post a picture of yours and then an answer is more likely.

There have been generations of early Kubota's with 3 wire dynamos.

One phase (2 of the 3 wires) went to the light switch bypassing the regulator/rectifier and the lights ran on AC current as some owners who installed LED lights found out when they would not work.

Since you have a multimeter, try using the AC voltage scale and check between pairs of the 3 alternator wires when they are disconnected and engine running at high rpm's and report back.

Dave
 

Dave_eng

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Here is a wiring diagram of your vintage tractor with 3 wire dynamo.




There are some dynamo's with 4 wires.

Testing for AC voltage output will tell the tale.

Dave
 

100 td

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The aussie kubota parts site, shows an alternator with brushes, I realize it may be different than the US model, but an alternator "may" be a possibility. A lot of dynamo's out there though!
 

BruceP

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It is pretty trivial to test a dynamo with an ohmmeter. Just disconnect to isolate it from the circuit before testing.

Personally, I would take about 5 measurements with voltmeter with engine running and KNOW what the problem is and what needs done to fix it.

HINT: Judging from the schematic posted above, the dynamo is simply a center-tapped coil. I would expect the 'regulator' contains some diodes and then shunts any excessive voltage to ground. Use an AC voltmeter (which can handle frequencies higher than 60hz) to test if there is any AC voltage riding on the +12 line. This would indicate bad diodes within the regulator.

ANOTHER HINT: Remove, clean, and reinstall ALL ground connections before you declare any parts faulty. (disconnect battery negative before doing so)
 
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Dave_eng

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The aussie kubota parts site, shows an alternator with brushes, I realize it may be different than the US model, but an alternator "may" be a possibility. A lot of dynamo's out there though!
100 td
I just re read the L175 WSM and was surprised.

Models L175·L225·L225DT
ALTERNATOR. A Nippon-Denso alternator is used. Rated output is 10
amps.

CAUTION: Alternator output wire is in direct circuit with positive battery terminals and is "hot" at all times that battery is connected. Use caution when disconnecting or connecting terminals that output wire is not grounded.

The image shows an armature with brushes like a generator and in fact the word generator is used in the description.

In short, I guess it is not a dynamo and for that reason is likely expensive to get the original design.

With an output of 10 amps, it may be time to change to a 20 amp dynamo and appropriate regulator/rectifier but some re-wiring necessary.

Dave
 

100 td

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If I was working on any kubota that had dynamo/alt/reg problems I would be looking to see if something like this could be fitted. I haven't checked it but general look to me says it's internally regulated. You then get rid of everything except power from ign and lamp.
https://www.ebay.com/itm/302341960595?
 

100 td

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The image shows an armature with brushes like a generator.
So it's showing an armature and commutator, or a multi-pole rotor with slip rings?
EDIT: Ok found the manual, shows a generator with commutator for L210-L260 and a slip ring alternator on L175-L225. What I also found on OTT was a wiring diagram for the L175 showing the alternator, even though its called a dynamo on the drawing, it's actually an alternator. So this may be the correct diagram for the L175 with alternator?

www.orangetractortalks.com/forums/attachment.php?attachmentid=3542&d=1306467235
 
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In Utopia

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L175 FEL
Apr 21, 2013
590
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Utopia,Tx/Pasadena,TX
Since electricity is not my friend I have a game plan.
There is a rebuild shop 10 minutes from my other home and I'll be back there Wed.
Took it off yesterday and I'll let them pass judgment on what I need to do.
 

100 td

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Have just updated previous post with new wiring diagram and info.
 

100 td

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I'll add some more, before you spend $, consider this, your alt has 6 diodes and 2 brushes in it, I'm betting if the brushes are OK, the alternator will work. So either brushes or the regulator will be at fault (if your wiring is correct). "IF" another alternator fits it like I mentioned from ebay, you get a 40A internally regulated unit for ~$70.
Have a read of a similar post here.
http://www.orangetractortalks.com/forums/showthread.php?t=34471
Either may not fit, or you may wish to stay original, your call. YMMV.
 

Dave_eng

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So it's showing an armature and commutator, or a multi-pole rotor with slip rings?
EDIT: Ok found the manual, shows a generator with commutator for L210-L260 and a slip ring alternator on L175-L225. What I also found on OTT was a wiring diagram for the L175 showing the alternator, even though its called a dynamo on the drawing, it's actually an alternator. So this may be the correct diagram for the L175 with alternator?

www.orangetractortalks.com/forums/attachment.php?attachmentid=3542&d=1306467235
This is what I find. Unique to L175, 225 & 225dt


A lot of components for 10 amps.

Of course you could put on a 100+ amp, one wire Delco and have no power left to move the tractor :)

Dave
 

In Utopia

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L175 FEL
Apr 21, 2013
590
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Utopia,Tx/Pasadena,TX
Got back to town, dropped the alternator (not dyno) off at the repair shop. Going to have it rebuilt.
To many junk new ones coming from Korea. At least I know I'll have what I'm supposed to have.
Good night all.
 

100 td

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I would recommend you continue your old this thread and delete the other one, you have all the info needed here.
EDIT: Disregard the following statement as it appears on wire units have no provision for lamp circuit, so just main wire to starter or battery.

Main wire to battery, one wire to IGN switch, one to lamp. You have wires going from the alt to the reg and from the reg to the switches, use them, join them, mark up your wiring diagram.
 
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In Utopia

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L175 FEL
Apr 21, 2013
590
93
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Utopia,Tx/Pasadena,TX
Since I can't delete the whole thread (at least I don't think I can) I will continue here by asking what you are trying to tell me.
Sounds like you're suggesting using one of the the new style and using spade connectors like I mentioned.
 

100 td

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Re-read my posts, ,#3, #11, #12, #15.
In this thread I have already mentioned the possibility of fitting another alternator, internally regulated, ~40A, with ebay links, references to other threads etc. I also mentioned they have battery, Ign and lamp terminals.