Electrical & Lights Battery or Alternator fault

Discussion in '7th Generation (2003-2008) [Acura TSX]' started by westcorkaccord, Tuesday 3rd Sep, 2019.

  1. westcorkaccord Club Member ★ ☆ ☆ ☆ ☆

    VW-Honda Ireland
    129
    12
    2008 saloon EX 2.2 with 207722 miles on clock. First day alternator and three year old Bosch silver S5 battery. 20 miles into my 31 mile return home for work, the VSA warning light came on, then the ABS one. Then a few secons later, they go off, back to noral and a few seconds later off we go again. Dip headlights were on at the time. Wipers were on for about 5 miles( did not notice any slowing down of wipers) engine felt OK. I then said I would do a reset by restarting, car would not restart, dash light flashing. Got out my Fluke AC/DC voltage and current meter and 11.5 volts on battery, when I turn the key, dropps down to 5.8volts. Got my son to call around and he has a 1.6 TDI 2012 Jetta. Connected up for ten minutes and without the VW started the flow was 2.8 amps to the Honda. Once started 17Amps, and 21Amps at the end. Started car and drove home the ten miles, kept all aux power off. Felt ok going home, no warning lights on. When home, kept it running. Voltage is 13.5 and turning on the lights with the car ticking over, you hear the engine revs go up and the back down after the lights go off, this would say the alternator is working ok. No power or starting issues ever with the car. I need to get a new battery for a generator, so I might put this in the booth for the next week and keep the jump leads in there as well. Any one have any problems like this before, say loose connections ECT?
     
  2. Heckler Club Moderator Club Staff

    Do you have an OBDII reader? If so, check for any codes....

    When ever I've had a battery starting to go on these, they've struggled to start... But work fine when running... But leave it for 24-48hrs without starting and she struggled to start again.
     
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  3. Sandy52 Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Sandy NORWICH
    297
    129
    Check your battery voltage first, engine off. If it is low then that is the likely cause. 11.5 volts on a car battery is LOW. Should be 13v or more preferably 13.5v.

    Not worth keeping a poor battery for anything it will let you down when you need it.
     
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  4. westcorkaccord Club Member ★ ☆ ☆ ☆ ☆

    VW-Honda Ireland
    129
    12
    No I don't have a OBDII reader.
    - - - Updated - - -
    One question is, if it is the battery, ( the car does 70 miles every day, with around two to four starts) would the alternator have been able to have keeped enough charge in the battery to have stopped the VSA and ABS lights from coming on.
     
  5. Sandy52 Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Sandy NORWICH
    297
    129
    A weak battery will always cause problems. With modern cars they can cause havoc.
     
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  6. Heckler Club Moderator Club Staff

    With that kind of mileage, it would have to... So from your description the alternator is supplying more than enough power to keep everything running. But the battery isn't really charging up anymore and/or is so degraded that it can't hold enough of a charge.

    It varies from car to car depending on the size of the battery they have, but it takes roughly 10-15 mins of driving to put back enough of a charge to recover what it takes to start it.
     
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  7. westcorkaccord Club Member ★ ☆ ☆ ☆ ☆

    VW-Honda Ireland
    129
    12
    I might for a few days, put a new battery into the booth. put a voltmeter into the 12 socket and keep an eye on things, before changing ethier item. I will at the weekend check all eathing points as all the visable connections up on top look ok.
     
  8. westcorkaccord Club Member ★ ☆ ☆ ☆ ☆

    VW-Honda Ireland
    129
    12
    Last evening I put on my voltmeter to the cig lighter. When car was stopped,(after a 10km spin) it was reading 12.5volts. When started it wentr to 13.8volts. While sitting in the car, i noticed the voltage going back down to 12.5volts for a about 30 seconds and back up again for about 2 minutes. This happen a few times but not with the same cycle times. I would have thought the alternator would be charging the whole time the engine was running or is there some operational reason for it cutting in and out.
     
  9. Heckler Club Moderator Club Staff

    The alternator pulley is connected to the crankshaft, the faster it spins the faster the alternator spins. So it's normal to see it idle around there. So long as it's reading more than 12v at idle... it should be fine.

    It's quite normal for the voltages to change as different loads on the system come and go. You may not even be aware of something electrical putting a load on the system. Or not realise that something as simple as turning on the ac/heat can have a dramatic effect... Try it at idle, turn on the ac and you'll see the engine idle speed increase without you touching anything to adjust for the extra load.

    If the alternator was faulty, you wouldn't be making multiple 70m round trips each day. The battery would have a constant drain on it instead of being recharged as you drive... and go flat. The fact that it isn't proves that the alt is ok and it's most likely a failing battery.

    A new battery is around £80, and as we will be heading into the winter soon... a good idea to replace it now rather than later.

    About 20 or so years ago (when the Hale-Bop comet was visible in the night sky, as we could see it whilst driving) I was driving back from Reading in a 3 car convoy when my battery light came on. Fearing I had an issue we all pulled over and checked over everything. We had no volt meter to check, and the idle speed wasn't dropping, the car wasn't spluttering and the lights weren't dimming.

    Assuming it was an alternator problem... we estimated that we'd have enough juice in a fully charged battery to get home (about 40-50 miles) if we drove with minimal electrics running (it was late at night).

    So with me in the middle of our little convoy, I put only the side lights on, no music, no heat (luckily it wasn't a cold night), and it was a more basic car back then... I made it home without any issues at all.

    Now the alternator had only been replaced 4 months earlier. So I picked up a second hand one from the scrappies and fitted that... and took the old one back to the place I bought it.

    They tested it and found that the regulator had failed... which meant it was still charging normally but wasn't indicating that it was... I think it was something as simple as a failed diode.

    They fixed that and gave it me back... but that second hand alternator never failed and I never bothered putting the new one back on... When I sold the car a few yrs later... I sold the alternator too.
     
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  10. westcorkaccord Club Member ★ ☆ ☆ ☆ ☆

    VW-Honda Ireland
    129
    12
    Thanks for that, when I did the test, the car was at idle for the whole of the test with all power off, but for the drivers door open. One noise I did notice was a slight clatter which seemed to be coming from the area of the alternatior ( hard to pin it down) it was not consistent and not a worn bearing HUM. But it was not there before.
     
  11. Heckler Club Moderator Club Staff

    Does the sound change when you rev the engine... any kind of belt/bearing noise will do so.
     
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  12. westcorkaccord Club Member ★ ☆ ☆ ☆ ☆

    VW-Honda Ireland
    129
    12
    I was unable to test that as I was on my own, but from standing outside the car and reving it with my left foot, I did not hear any increase in noise. ...Others bits of information..The cable to the clutch of the A/C compressor is disconnected with about a year( it siezed). A new belt was fitted about 10 months ago. Before the new belt, but only once or twice since, in the morning when egine was cold, there would be a belt high pitch noise as I would drive off and after about twen second is would stop.