Auto Electrician SE London

Discussion in 'General Chat' started by Digger, Dec 19, 2006.

  1. Digger

    Digger
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    Hi All

    Just had a new battery installed in my 96 reg BMW 328i hoping that would cure the charging problem...but its gone flat again after only 2 days of inactivity. I have looked for all the usual suspects such as glovebox/boot lights, etc. So I suspect either alternator has died or suspect something is discharging the battery.

    Does anyone know of any auto electricians in SE London (Camberwell area)?

    Many Thanks
    Digger
     
  2. Ronski

    Ronski
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    Disclaimer: This advice is given in good faith - you carry out any work at your own risk

    I dont know of one in SE London, but I do know of one down here in Broadstairs, if your interested post back.

    To check to see if something is draining your battery do the following, you will need a ammeter reading up to 10 amps with crocodile clips.

    1. Make sure your battery is fully charged - use a separate charger
    2. Now with the battery on the vehicle, just connect the positive lead
    3. Make sure all doors are shut and everything is off, keys in your pocket! (Some alarms lock the doors when you connect batteries!)
    4. Now connect an Ammeter between the battery earth cable and the negative terminal of the battery - you will most likely now need to turn the alarm off.
    5. This will show how much current is being drawn, this should be minimal, less than 0.8 amp
    6. If this is less than 0.8 amp then it probably your alternator
    7. If it's more than 0.8 amp then isolate circuits by pulling out 1 fuse at a time and seeing what affect it has.



    I repair commercial vehicles with 24v systems so I'm not exactly sure of what current draw you should have, but I would say 1 amp is probably a bit high. On a truck the current draw is about 0.4 amps 24V, so 12V would be about 0.8

    You battery may be fine, you may have a bad earth connection, there are connections from the battery to the vehicle body and also to the engine, check that these are good - take them off and check they are not corroded, this is often mistaken as a flat battery! The connections to the starter and alternator could also cause the vehicle not to start/charge.

    To check for bad engine earth put a jump lead between battery - Negative and I nice solid piece of engine metal and then try starting (With battery properly connected and the lead clear of any moving parts)

    Edit: You say two days of inativity - so I presume you have not driven it - if so then it's not an alternator problem, it's either a drain, bad connection or faulty starter motor.
    Hope this helps
     
  3. Digger

    Digger
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    Thanks Ron. Your advice is very much appreciated :). I dont have an ammeter, and I would love to carry out the tests myself. But have decided to hedge my bets and taken the car round to a local auto-electonics "wizard". Lets hope for the best. Just hope he knows what he is doing.

    Thanks again.
     
  4. Ronski

    Ronski
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    At least you are now better imformed as to what it could be.
     
  5. gus607

    gus607
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    Had a similar problem a while back, turned out to be the alternator.
     

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