03 ultra charging problem

Discussion in 'Electrical' started by marcus22, Jul 25, 2013.

  1. marcus22

    marcus22 Junior Member

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    Hey all,

    Heres the deal! While driving down the road i noticed my volt meter at 11.5 ish. and soon after the battery went dead. its a brand new battery and when fully charged and running it never get above 12.5 at any rpm. I have the bike home now and looked up "testing the charging system" in the self help section and went through the steps. I have a couple questions though and here are my findings. I colored the steps blue=pass, red=fail, and orange=maybe

    on Step 2, I found no light on a test light but i did find 11.6vdc on a digital meter, but only on one prong and nothing on the other. bad right?


    Step 2. To check the regulator unplug it from the stator. Take a test light and clip it to the negative terminal of the battery and then touch first one pin and then the other on the plug that goes to the regulator. If you get even the slightest amount of light from the test light the regulator is toast.

    To do this with a meter which is more accurate: black lead to battery ground, red lead to each pin on the plug, start with the voltage scale higher than 12vdc and move voltage scale down in steps for each pin. Any voltage is a bad regulator.
    You may get battery voltage on all three pins on the newer 3 phase regulators.
    The no voltage is for older type regulators with diode indicating the diode is bad and the regulator needs replacing.


    on step 3 i did find 0.2ohms. Good right?

    Step 3. On the other part of the disconnected regulator plug. Set the multimeter for Ohms x1 scale and measure for resistance across the pins of the stator. You should read something around 0.1 to 0.2 ohms for the TC88 32 amp system.


    for step 4. What selection on the volt meter should I check this? and where would the best place to check be? I did check from the stator prongs to a few different bolts where the motor connects to the frame. i did get 0.2-0.3 for a reading. Bad right?

    Step 4. Then check for continuity between each pin on the plug and frame/engine ground. The meter needle should not move (infinite resistance)(digitals will show infinite resistance) if the meter needle does move (indicating continuity)(digitals will show some resistance), recheck very carefully. If the meter still shows continuity to ground the stator is shorted (bad).

    on step 5 I only got 3.0vac at idle. bad right?

    Step 5. Set the meter to read A/C volts higher than 30 volts (the scale setting for voltage should always be higher than the highest voltage you expect or you may fry the meter). Start the bike, and measure from one pin to the other on the plug (DO NOT cross the multimeter probes! - touch them to each other). You should read roughly 16-20 vac per 1,000 rpm.

    so....what do you think? could both be bad? i did replace the regulator about 30,000 miles ago.

    any help is much appreciated

    thanks,

    marcus
     
  2. tourbox

    tourbox Senior Member

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    On your step 2 I would think that 11.6 Vdc would have made the light illuminate. Yes I would say it is bad. For step 5, I agree it is also bad. You should of had more Vac at idle. I normally will rev. up to check for Vac increase also. My VOM has a beeper that I use for the stator ground test,if it beeps then it is grounded and bad,
    tourbox
     
  3. Hoople

    Hoople Account Removed

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    That low charging voltage is probably caused by a voltage drop across the circuit breaker. (see attachment) That will eat parts alive.
    Once you get the system charging again, focus on why your charging voltage is so low at idle.

    Check overall voltage drop of the charging system by measuring the difference between the voltage directly out of the voltage regulator vs the voltage directly across battery. Should not be much more than .15 volts.
    Using 2 meters makes it easy to perform at different RPM's.
     

    Attached Files:

  4. marcus22

    marcus22 Junior Member

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    How do you check the voltage directly out of the voltage regulator? and are you saying both the voltage regulator and stator are bad and fix them first?
     
  5. Hoople

    Hoople Account Removed

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    You know I'm not the only one.. I know of several knowledable people here that you yourself taught. :s

    But thanks for the kind words!:)
     
  6. Jack Klarich

    Jack Klarich Expert Member

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    No need to be modest, you are Definitely the GO TO GUY when it comes to electrical and I am glad you are here:s
     
  7. Jack Klarich

    Jack Klarich Expert Member

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    Hoople will correct me if I am wrong, you have battery voltage lead returning to the battery from the regulator, I would back probe that lead and use other probe at close ground to the regulator, there by getting a more accurate reading before the battery posts
     
  8. Hoople

    Hoople Account Removed

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    Disconnect the stator from the voltage regulator. Using your ohm meter on the 200k range, test each pin of the stator to frame ground. You should read infinity. If not, the stator is bad.
    Last time you changed the regulator did you use a Genuine HD.

    For voltage drop testing. Use very thin sewing needles to pierce the wire insulation at the voltage regulator. Hook your neter to the pins. The meter needs to be good quality and accurate. Use the 20 volt scale in order to read to two places. (12.XX)

    Compare that reading to a reading directly at the battery posts.
    Theoretically they should be the same reading but they won't be. The difference is the voltage drop or wasted charging voltage.
    You must keep that number as low as possible.
     
  9. marcus22

    marcus22 Junior Member

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    thanks, i will check tomorrow when i get off work. I think i used a Genuine HD regulator. it was from the dealer.

    when i test the regulator output vs. the battery, if it is a high difference in number what does that mean?
     
  10. Hoople

    Hoople Account Removed

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    It means that some of your regulator output is being wasted instead of charging the battery. The difference between a battery not being charged at all (12.70 volts) and the battery being overcharged (14.70 volts) is only 2 volts. It's easy to think it's 12 volts and not just 2 volts, but it's just 2 volts..

    So if you measure a voltage drop of just .50 volts, that really represents 25% of the stator's total output being wasted. That means the stator & regulator needs to work overtime just to keep up with the loses of poor connections.. The regulator and stator will now be on overtime and will run hotter than they should. If your lucky, a diode will open when the regulator finally gives up. But if it shorts, the stator is 30 minutes from its death.