No charge, no speedo

Discussion in 'General Motoring' started by Spdloader, Jul 1, 2006.

  1. Spdloader

    Spdloader Guest

    Hi, I'm new to the group, but my daughter has a Honda now so I'll be
    I didn't find anything on this exact problem in a search so:

    Vehicle is a 1998 Civic DX 5spd.

    Dead battery prompted a test of the alternator, which wasn't charging at
    Replaced alternator, and externally charged battery overnight. The car
    started fine the next morning, and it worked fine for about 1/2 a day,
    charging between 13.8v and 14.2v, then the speedo quit working, then that
    evening the headlights were dim.

    Next morning, battery was weak again, I charged the battery for a while,
    then started it, but now there is a no charge condition again, verified with
    a Fluke meter at the battery, but not at the alternator.

    A brief check of the fuse block under the dash revealed a blown 10A fuse,
    Alternator / Speedo. Replaced it, had a charge at the battery, then blew the
    fuse when moving the vehicle in the driveway.

    I suspect the vehicle speed sensor has a bad connection or is
    malfunctioning. Any other ideas before I dive back in tomorrow?

    Thanks in advance!

    Spdloader, Jul 1, 2006
  2. ------------------------------------------
    Disconnect the battery for 30 seconds, then reconnect without
    'spitzensparken'. You might just need to clean up the 'boot' for all the
    electronics. The don't like low voltages and errors creep in. Odyssey is
    worst because many sliding doors and interior lights (and kids). Owners
    spend hundreds on towing and 'diagnosis' when all they needed is a
    recharge and a disconnect.

    'Curly Q. Links', Jul 1, 2006
  3. Spdloader

    Pdigmking Guest

    How did you test the alternator? Have you done a load test on the
    battery? Check the connections on the alternator and the battery, make
    sure your wired right and getting good connections. Make sure the
    alternator belt is correctly tightened. These are the basics. If all
    this is OK, and you the 30 second battery disconect and it still acts up,
    I say you have a dead short somewhere in the system. You may have gotten
    a bad alternator with a faulty voltage regulator.

    Pdigmking, Jul 1, 2006
  4. Spdloader

    Spdloader Guest

    Thanks Curly, I gave it a try, but it didn't change anything.

    Spdloader, Jul 1, 2006
  5. Spdloader

    Spdloader Guest

    I was a professional mechanic for 15 years, but haven't the experience with

    Original alternator tested and diagnosed with an AVR. Battery was properly
    load tested.

    Alternator was tested with a Fluke meter the second time.

    I already covered the basics, but I appreciate the ideas.

    The alternator is charging at the alternator, but not at the battery. That
    rules out the alternator.

    The alt/speedo fuse keeps blowing to prevent it from charging the battery,
    which is why I suspect the VSS.

    Spdloader, Jul 1, 2006
  6. Spdloader

    pars Guest

    Hi Spdloader,

    I've been lerking around this news group for almost a decade now and
    just sold my 98 Civic Hatch to this a bodyshop guy who was going to
    give it to her daughter (hope u're not the same). I'd hate to think the
    car is being difficult, when it has been very good to me.

    Anyways, you're the first person I've encountered that's having an
    electrical short in the system for this model. If you're not making any
    grounds, I'd recommend disconnecting any of the aftermarket stuff (if
    any) and go from there.

    pars, Jul 2, 2006
  7. Spdloader

    Spdloader Guest

    Thanks, so far I've been unable to find anything amiss in the circuit, I
    cleaned the VSS connection, cleaned the connections at the alternator again,
    and cleaned the connections at the battery again. I have unwrapped the
    wiring loom looking for a short, but have found nothing, after checking
    about halfway up the line. I intend to finish up with that later today after
    the outside temps go down. Too freakin' hot out right now to be leaning on a
    metal car.

    Oh, and this one's not a hatchback, it was a hand-me-down from her step dad.

    Spdloader, Jul 2, 2006
  8. Spdloader

    Spdloader Guest

    With the fuse replaced, at idle, the new alternator charges 13.9v, as soon
    as you rev the motor the tiniest bit, the alt/spd fuse blows.

    I'm guessing, I've got yet another bad alternator.

    Spdloader, Jul 4, 2006
  9. Spdloader

    Earle Horton Guest

    You can get an inexpensive magnetic ammeter from many auto parts or tools
    vendors. You just lay it over the wire, and it tells you how much current
    is passing through it. I'm guessing bad alternator too.

    Earle Horton, Jul 4, 2006
  10. Spdloader

    Spdloader Guest

    Thanks Earle, the probe accessories on my Fluke meter allow me a similar
    setup. Hard to believe three bad alternators with exactly the same problem.
    1, the original, 2, the one from the salvage yard, and 3, the reman unit
    from the Zone.


    Spdloader, Jul 4, 2006
  11. Spdloader

    Matt Ion Guest

    I find that hard to believe as well - I'd start looking for either
    another source of the current draw, or something else that may be
    killing the alternators (probably with excessive current draw).

    I missed the original thread, but have you tested and/or replaced the
    battery? An internal short may be sucking the current. Maybe check for
    a short in the alt-to-battery wire (rubbing against the block?)

    Hmm, 13.9V is really too high for idle... you should normally see closer
    to 12.5V at idle (<1000rpm), and 14-14.5V when revved up.
    Matt Ion, Jul 4, 2006
  12. Spdloader

    Spdloader Guest

    This is a no-frills car. No power windows locks or anything, just a stereo
    and rear window defroster, which did have a blown fuse.
    The battery was properly tested with an AVR, and the charge harness has been
    dissected and nothing notable found. VSS removed, tested, cleaned, and
    That was immediately after putting in a new fuse, and the alternator started
    charging. It quickly about (1-1/2min) went down to the 12.5 range and
    maintained it, but upon revving the engine, the charge went off the scale
    and the fuse blew again, all in about 2 seconds. Charge started down the
    scale then.

    Spdloader, Jul 4, 2006
  13. Spdloader

    Graham W Guest

    It really looks like the current alternator is not regulator it's full
    voltage output and the battery is kind enough to mop up the extra amps
    until the Fuse get bored and decides it's time to leave.
    Graham W, Jul 4, 2006
  14. Spdloader

    Graham W Guest

    It really looks like the current alternator is not regulatING it's full
    speed voltage output and the battery is kind enough to mop up
    the extra amps until the Fuse gets bored and decides it's time to

    Sorry for the typo.
    Graham W, Jul 4, 2006
  15. Spdloader

    Earle Horton Guest

    This looks like problems with the voltage regulator. I am not sure where it
    is located in a "1998 Civic DX 5spd", and I hope I never find out, because
    mine is a 1999 HX, probably in the same place!

    Earle Horton, Jul 5, 2006
  16. Spdloader

    Spdloader Guest

    You know what sucks the worst, Earle? She gave up the '90 XJ Limited I gave
    her for this thing. It never gave a moments trouble, just liked the gas.

    Spdloader, Jul 5, 2006
  17. Spdloader

    Matt Ion Guest

    Strange... if there was a short to ground somewhere, the voltage should
    plummet just before the fuse blows. Does it still do it with the
    battery disconnected?

    It sounds like a bad voltage regulator, but that should be internal on
    those alternators and so you'd be getting a different one with every
    replacement alt.
    Matt Ion, Jul 5, 2006
  18. Spdloader

    Matt Ion Guest

    If I'm not mistaken, the regulator is internal to the alternator, which
    makes it that much stranger that this should happen with three different
    Matt Ion, Jul 5, 2006
  19. Spdloader

    Spdloader Guest

    Makes no difference if the battery is connected. Same outcome.

    Tomorrow, it's a new alternator.

    Update to follow.

    Spdloader, Jul 5, 2006
  20. Spdloader

    Graham W Guest

    Well, if it's not the battery mopping up all the amps til the fuse pops,
    then it must be a short to ground.

    Have you tried it with the high current stuff (headlights etc) on and
    then measure the volts as the revs are raised?
    Waiting with baited breath.
    Graham W, Jul 5, 2006
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