Page 1 of 3 123 LastLast
Results 1 to 10 of 22
  1. #1
    Platinum Member
    Join Date
    Aug 2003
    Posts
    502
    Location
    Tulsa OK
    Tractor
    Ford 3000

    Default Generator charge circuit troubleshooting

    Finally finished the hydraulics overhaul on my Ford 3000 this morning. Had a little trouble getting it started, replaced the fuel filter but the book didn't tell me I also needed to bleed the injector pump. All it said was to bleed the filter, hard lesson. In any case I had a battery charger connected to it when it started, not sure if the charger had anything to with it or not but now the generator light stays on.

    The IT manual is pretty much worthless except it does have a wiring diagram. I haven't worked on a generator charging circuit since the early 60's and am pretty much at a loss as to how to trouble shoot the charging circuit. Have a good meter and am pretty good with electrical stuff but don't want to jump in blindly and mess something up that may not be broke.

    Can someone run through a basic troubleshooting procedure for a generator charging circuit? Like can I just stick 12 volts on the field to see if the generator is working without smoking anything? How does one determine if the regulator is working?

    thanks
    Bob

  2. #2
    Platinum Member
    Join Date
    Aug 2003
    Posts
    502
    Location
    Tulsa OK
    Tractor
    Ford 3000

    Default Re: Generator charge circuit troubleshooting

    Looks like it may be the regulator. Just started it again and had 13.0 volts at the battery and milivolts on the field. Will have to pull the hood off to get good access to the regulator but am I headed the right direction?

  3. #3
    Super Member Highbeam's Avatar
    Join Date
    Feb 2005
    Posts
    5,039
    Location
    South Puget Sound, WA
    Tractor
    Kioti CK30HST

    Default Re: Generator charge circuit troubleshooting

    Keep in mind that a nice new GM one wire alternator is only like 50$. With new regulator, bearings, etc.

    When my IH dozer was charging at 18 volts (can you hear the battery boiling?) I just did the quick and easy GM 1-wire instead of repairing and troubleshooting the old system. It turned out very well in that case.

  4. #4
    Gold Member uhmgawa's Avatar
    Join Date
    May 2003
    Posts
    283
    Location
    New Hampshire
    Tractor
    Kubota L48TLB

    Default Re: Generator charge circuit troubleshooting

    </font><font color="blue" class="small">( Looks like it may be the regulator. Just started it again and had 13.0 volts at the battery and milivolts on the field. Will have to pull the hood off to get good access to the regulator but am I headed the right direction? )</font>

    I'd say so. But unless you find a simple mechanical
    problem such as a bad connection it would probably
    be easier to swap the alternator with an automotive unit
    of similar footprint. Doing so you will likely increase
    your charging system's ampacity as well.

  5. #5
    Silver Member
    Join Date
    Aug 2005
    Posts
    201
    Location
    Eastern KS
    Tractor
    JD 4100 HST CUT w/Yanmar 3TNE74 | JD 300 Lawn

    Default Re: Generator charge circuit troubleshooting

    Presumably you have a unit that outputs DC directly. I have a JD 4100 that outputs AC to a rectifier/regulator which complicates matters. I posted a similar thread here - may want to read. At this point, it seems my whole problem was poor connections. A VM attached to the battery w/engine on now reads 12.5-14. I traced all the wires from alternator to battery. Alternator was delivering 20-50v (low-high rpm) AC. I found many dirty connections. There were also protection relay's and diodes. They all seem to be OK, but presumably somewhere in the path I had bad connections, as I could never keep a charge on the battery. Now I appear to be OK.. with &gt;12V DC and amps flowing on the battery cable when I run it.

  6. #6
    Platinum Member
    Join Date
    Aug 2003
    Posts
    502
    Location
    Tulsa OK
    Tractor
    Ford 3000

    Default Re: Generator charge circuit troubleshooting

    Opened up the regulator and wow what a mess of corrosion and burnt contacts. NH says $35.00 for a new one and have 4 in stock, will probably go that route after I make sure the generator is OK. Still wondering if I can stick 12 volts on the field wire to test the gens output?

    Wouldn't mind upgrading it to an alternator and the additional power would be welcome but don't want to loose my tach and hour meter which runs off the back of the generator. Afraid it would end up a can of worms with a special aftermarket alternator. The generator does fine when it's working.

  7. #7
    Gold Member uhmgawa's Avatar
    Join Date
    May 2003
    Posts
    283
    Location
    New Hampshire
    Tractor
    Kubota L48TLB

    Default Re: Generator charge circuit troubleshooting

    </font><font color="blue" class="small">( Opened up the regulator and wow what a mess of corrosion and burnt contacts. NH says $35.00 for a new one and have 4 in stock, will probably go that route after I make sure the generator is OK. Still wondering if I can stick 12 volts on the field wire to test the gens output?)</font>

    IIRC energizing the field winding directly with 12V you will get
    a much higher output voltage from the generator. So if you
    do so make sure the output of the generator isn't feeding back to
    the battery/electrical system.

    </font><font color="blue" class="small">(
    Wouldn't mind upgrading it to an alternator and the additional power would be welcome but don't want to loose my tach and hour meter which runs off the back of the generator. Afraid it would end up a can of worms with a special aftermarket alternator. The generator does fine when it's working. )</font>

    Ah, ok. Didn't realize there were other dependencies. At $35 for a
    new regulator that isn't too bad. Contrast that with a new 40AMP
    alternator in my L48 weighs in over $600 -- HA!

  8. #8
    Platinum Member
    Join Date
    Aug 2003
    Posts
    502
    Location
    Tulsa OK
    Tractor
    Ford 3000

    Default Re: Generator charge circuit troubleshooting

    Thanks for the help, found this in an old thread on Yesterdays tractors, sorry didn't get the posters name. Think it was quoted from the Ford service manual. Sounds like a safe way to check the generator...
    **************************
    Disconnect the two wires from the terminals on the generator noting which went where.

    Jumper the two terminals.

    Connect a 20V DC volt meter to one of the terminals and the black/common lead to ground.

    Crank the tractor and run at ****IDLE SPEED****

    note the voltage reading.

    Slowly increase the engine RPMs

    The generator voltage should rise smoothly and rapidly with RPM's.

    Do not allow the voltage to exceed 20V's and do not run the tractor for long wired like this. If the voltage rose smoothly and rapidly above 15 volts and holds steady at the same RPM's then the generator is working most likely.




  9. #9
    Gold Member uhmgawa's Avatar
    Join Date
    May 2003
    Posts
    283
    Location
    New Hampshire
    Tractor
    Kubota L48TLB

    Default Re: Generator charge circuit troubleshooting

    </font><font color="blue" class="small">( Disconnect the two wires from the terminals on the generator noting which went where.

    Jumper the two terminals. )</font>

    Hmm. Looks like this is expecting residual magnetism
    in the stator/field to self-excite the generator and drive
    the field at a reduced voltage. If this shouldn't work (ie:
    no voltage output from the generator) you can remove
    the jumper and try to drive the field at a low voltage with
    the engine at idle. An adjustable DC power supply would
    be ideal here but if you can find a dash dimmer switch and
    a 12V battery that would work as well. Make sure you have
    2V or less going into the field before the rotor is in motion.
    If you can't get the voltage across the field down low enough
    try adding a light bulb as a dummy load in parallel with the
    field winding.

    You can increase engine speed and/or field voltage+current
    to verify this causes a corresponding increase in generator
    output voltage.

  10. #10
    Platinum Member
    Join Date
    Aug 2003
    Posts
    502
    Location
    Tulsa OK
    Tractor
    Ford 3000

    Default Re: Generator charge circuit troubleshooting

    Generator passed the test, off to NH to pick up a regulator. While I was at it cleaned all the conectors so as soon as I get back with the regulator it should be good to go.

    Thanks,
    Bob

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.