2000 Honda Accord EX - Cold start problems (parasitic battery draw)

Discussion in 'Accord' started by athlonDon, Dec 10, 2005.

  1. athlonDon

    athlonDon Guest

    Hopefully someone out there can help me on this one.

    Starting last week, I started having problems starting my 2000 Honda
    Accord EX. The engine would not turn over because the battery was too
    low (Lights would dim when trying to start etc). So I had a buddy of
    mine give me a jump and drove home. I then put a volt meter on the
    battery to find I had 12.X volts on the battery. The next morning
    (after a VERY cold night in the garage) the car battery was all but
    dead, the door locks wouldn't even unlock from the key fob. So I put
    the battery on a charger overnight so that I could take the car into
    the shop the next morning. The Honda Dealership shop replaced the
    batter (a 9 month old battery at the time) to no avail; two days later
    the car wouldn't start again. BTW I also have a brand new alternator
    on the car as well (as of 5/2005). So off to the shop I go again (this
    time I did not have the volt meter at hand as I was at work, but I am
    sure the volt meter would have shown the battery was drained). The
    shop kept the car for 2.5 days and even left it out in the cold only to
    find no draw on the battery and the car started like a charm every
    time. They even thought it might be a problem with the starter but
    admitted it was unlikely the culprit. So I took the car home knowing
    it would most likely happen again, but this time I would make sure to
    keep the volt meter handy. As soon as I got the car home I put the
    volt meter on the battery (with the car off) to find the battery charge
    at ~12.4 volts. Later that night we drove the car out to a friends
    house and back and before I went to bed I checked the battery again
    ~12.8 volts (at roughly 12:00am). When I first got up in the morning I
    checked the battery again ~11.4 volts (@ around 7:00am). About an hour
    and a half later I put the meter on again to find the charge at ~10.5
    volts. Knowing it probably wouldn't start I tried to start the car and
    sure enough it would not turn over.

    BTW, I am sure the alternator is good and charging the battery, as I
    put the volt meter on the battery with the car started to find ~14.4

    So obviously it appears I have a significant parasitic draw on the
    battery occurring on the car. Especially considering it drew down the
    battery almost a full volt in the course of an hour and a half. The
    troubling thing here is that it appears to be sporadic. Thus when I
    take it into the dealership they can't find a problem with it.

    One other thing to note, I noticed the day before we started to have
    problems with this car that when driving down the road sometimes you
    would hear something like the air conditioner compressor (or something)
    even though the heater and the radio or completely turned off. It
    sounds just like when you first turn on the A/C, almost like a
    mechanical whir. This noise is sporadic and occurs both when the car
    is moving and stopped. Maybe this is just a coincidence, but I thought
    I would bring this up.

    So my question is what should I do about this issue? I am not very
    mechanically inclined and I need a reliable car. I thought for sure
    the guys at the Honda dealership garage would figure this out, and I am
    afraid if I keep taking it in they are going to keep giving me the same
    line (that they can't find anything wrong with the car).

    Any help/insight would be appreciated.

    athlonDon, Dec 10, 2005
  2. athlonDon

    Mark Guest

    could be complicted or could be simple

    simple like the trunk light or glove box light is on?
    underhood light?
    any alarm system?
    extra audio stuff 2 way radio, cell phone etc not shut off?

    if you have a digital voltmeter with a sensitve mV scale you can approx
    measure the current without disconnecting anything...

    check the meter offset by just shorting the two probes together (not
    connected to the car)... the meter should read 0 mV...if it doesn't
    then just use whatever it does read i.e 1 mv as the 0 value.

    now connect the - lead of the mV meter to the negative post of the
    battery and the + lead of the meter to the chassis of the car.

    you are now measuriung the mV voltage drop across the battery ground
    cable. put the head lights on (car off) and see what the reading
    is... should be maybe 50 mV.

    Then turn everything off,,, if you still get a reading say 5mV then
    whatever is still drawing current is drawing about 1/10 of what the
    headligts draw .

    with the car off, and the meter connected as described above it should
    read 0mV (or whatever your meter offset reading was)

    this only works with sensitve voltmeters that have mV (millivolt)
    scale... millvolt = 1/1000 of a volt so you are measuring the very
    small voltage drop across the battery cable as a way to measure the
    current draw...

    Mark, Dec 10, 2005
  3. athlonDon

    athlonDon Guest

    Thanks for your quick response. Yeah I have a digital multimeter
    actually (didn't know what it was called before). I will give that a
    try if the mechanic can't fix it. I just took the car into the
    dealership and explained everything to them. They called their
    mechanic out to talk with me thru everything I found (as I described
    above) and he said it might be a multi-plexor (sp?). I don't really
    know what that is/means, but apparently it could be causing for extra
    draw after the engine is shut off. Evidently they are supposed to shut
    down the system after 10 min. or so. but sometimes have been known to
    "stick" and thus draw too much from the battery. I will keep everyone
    updated and try your suggestions if this isn't it.


    athlonDon, Dec 10, 2005
  4. athlonDon

    SadaYama Guest

    Sounds like an interesting problem.

    How many miles on this car? At what mileage did you replace the
    SadaYama, Dec 11, 2005
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