A friend of mine is at his wits end with his X5 whose battery keeps going flat after a week or so.
It's been into the local BMW dealer numerous times, for new battery (x2), new ignition switch, new alternator (£1000!) but still the battery flatens after a week or so.
Any suggestions on a technical level, or recomendations for a company that will diagnose the problem?
Thanks in advance
MVP
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Doews it go flat while he is using it or when it has been left overnight?
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Andy
Had a new starter motor as well!
key indicators it still has the problem
1...turn ignition and ticks as if starter motor cannot turn ie not enuf power
2.. when you turn it off the radio stays on and you cannot turn it off unless you turn the car back on again
typically it appears to go flat over night rather than 1 hour later
but in answer it does not appear to happen when driving along
but normally on point 1 when you try the ignition again it works
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>but normally on point 1 when you try the ignition again it works
Its probably not the battery then. If it has enough power the second time, it had enough the first time. Something else stopped it starting. Engine to body earth would be one place to look.
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TourVanMan TM < Ex RF >
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He also said that after being on holiday for a week, the battery was completly flat and needed re-charging.
Also, the 1st new battery died because it went so flat
Could this still be an earthing issue?
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It could be that the earthing issue is not charging it fully. There may of course be more thanone problem
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TourVanMan TM < Ex RF >
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go back to the dealer and park beside another X5. Get the techies to meter the two car batteries and see if your friends is drawing more current when everything is (supposedly) switched off.
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I'd have thought that instead of pouring money into the dealer's pocket; it would be better to take it to an auto-electrics place.
The dealers clearly haven't got anyone that even understands how to test a battery/starter/charging system.
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I might possibly know the answer to this problem. Before going further, one question. Does this vehicle have a Becker radio?
659.
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I have seen a number of BMWs with erratic battery going flat syndrome caused by a fault with the heater blower staying alive with the ignition switched off.The motor runs very slowly but is enough to drain the battery overnight.The problem is fixed by renewing the electronic fan speed controller .Part cost about £60.hth
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You need to see if it is drawing any current with everything switched of ,simple task with a multimeter in series with the battery pos+ lead doing this will show if anything like MVP states above is happening.
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Thanks for all the suggestions guys
659 - he says it's part of the standard satnav installation
www.pistonheads.com/sales/largepic.asp?i=199123&no...5
Doctor, he's going to investigate the fan bit
MVP
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The car will draw current for several 5 or 6 minutes before the systems shut down. You will need to have the meter in series whilst the ignition is turn on the off again, remove keys and lock it, you may have to over ride the bonnet sensor to allow the alarm to arm. BMW 5 series pulled 4 amps from memory then 1.7 then 12 mins in 80 ma ( Alarm, clock rechargeable torch in glove box etc etc. ) Regards Peter
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Alll BMW dealers should have a data logger system that they can connect to the car to monitor the quiescent current drain on the battery. When the ignition is turned off there is a 'shutdown sequence' as the various ECU's etc turn off - there is a spec for this sequence and for the quiescent current drain and the dealer should compare this against the current graph show on the logger.
It could be many things. I had a 7-series that had a fault with the system that applies pressure to the wiper blades. On a 5-series I had a fault with the heater ECU - difficult to find but by chance I heard the heater valves randomly 'chatter' whilst I was working on the engine. In both cases the battery would go flat overnight.
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