W

Wellsy

Member
Went to the vehicle yesterday afternoon and battery flat enough there for lights on dash but not enough to crank over and start .

Called aa and due to bank holiday local garage come out they jump started it and tested it was charging ok which was fine he stated .

Told me to double check that no lights where left on which of course there wasn't .

Battery is new , come to the car this morning 12 hours later battery dead again.

Might be a coincidence but on central locking all doors opened except passenger front door just before I had the battery problem ie the morning before it decided to drain .

Any help would be apreciated as I'm waiting on the breakdown people coming out again to at least drop test the battery many thanks
Craig
 
What year is your wagon?. If it is older than a 2001 it is likely that the RF receiver is an older model which is susceptible to spurious radio signals. Weak signals will keep the BeCM awake thus flattening your battery pretty quickly. Stronger signal can result in complete lockout using the remote fob.

You can check the RF receiver fairly easily. It is located under the driver side rear parcelshelf mount. If it has a green dot and a CE mark then.it is the latest version. If the dot is blue you have one of the older models which will cause you grief when you least need it.
 
Sounds like the everlasting woe of the RF receiver - this is a little box which sends the signal from the radio key fob to the car computer. Unfortunately the standard unit picks up signals from pretty much everything, thus keeping the BeCM awake and thus draining the battery. It's a little black box under the rh rear parcel shelf. It's quite easy to inspect - put seat forward, and then there's one screw and a few plastic push in pegs. It has a wire cluster and a blue wire. If your box has a blue sticker on it, it's the original (problem one) and the fix is to remove the aerial (blue wire), which prevents it picking up spurious signals. The side effect is that the key range is then pathetic. The better (but sadly rather expensive) fix is to replace it with the newer unit - that has a green sticker. The old unit, in addition to ruining the battery, also has a habit of burning out the door locks.. which might explain your nearside front door :/

Could someone do a how-to on this (I'm happy to, can anyone upload them?)? This problem occurs so often...
 
Aa report won't start 12.0 volts and 0.04 amp drain

Carried out battery test volts 12.60 v
Measured 641 cca
Rating 760 cca
Battery good

Unloaded charging at 14.0
Loaded charging at 13.2 volts

Clamped battery earth cable 38 amps unloaded voltage dropped to 12.9 volts loaded and amps dropped to 4 amps

Possible alternator fault aa report states

Vechicle is a r plate dse Auto BMW engine
 
Wellsy said:
Update has blue sticker on it
Click to expand...

In the short term you could disconnect the blue antenna wire from the rx'er. This will reduce the units ability to pick up any signals and will give you a short term solution. It will also reduce the range of the key fob as well so you will need to be no more than a metre away from the unit when you open or close the doors.

New ones cost about £150 but there have been stories here of members getting them off eBay for much less.
 
jt_armstrong said:
New ones cost about £150 but there have been stories here of members getting them off eBay for much less.
Click to expand...
Tis true I've got one on mine, It's been on for two months now & I've not had a flat Battery since.
I had all the trademark problems, flat Battery after a couple of days, passenger lock burnt out & now It's all sorted & a dam sight cheaper then £150 I can tell thee. :)
 
That battery seems a little low....replace with a 1100cca battery (I think - ask Datatek he knows the right one!!)
 
Right new alternator and belt fitted unplugged the blue wire see what happens tomorrow all in all 170 for belt and new alternator so hope it's sorted now
 
Wellsy said:
Aa report won't start 12.0 volts and 0.04 amp drain

Carried out battery test volts 12.60 v
Measured 641 cca
Rating 760 cca
Battery good

Unloaded charging at 14.0
Loaded charging at 13.2 volts

Clamped battery earth cable 38 amps unloaded voltage dropped to 12.9 volts loaded and amps dropped to 4 amps

Possible alternator fault aa report states

Vechicle is a r plate dse Auto BMW engine
Click to expand...

Battery is too small for the diesel for starters. RF receiver is probably the cause of the drain. sort it before it burns your door locks:eek:
 
TCubed said:
Can you do that? Some told me the P38 would object to trickle charging?
Click to expand...

The only things the P38 objects to is crude old unregulated chargers, jump starts done incorrectly and low battery volts.
Many use solar chargers including me if it's going to be left at the airport for some time:)
 
Left car for 18 hours car fired up straight away not a problem now but I have unplugged rf receiver like told looks like next is a new battery seeing as its too small thanks all
 
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