Yet Another Weird Battery Drain Issue :: 2002 X5 3.0

[4reagan]

Looking for a bit of direction on troubleshooting a battery drain issue :: 2002 X5 3.0

Here's the history.

1. Battery light began flashing one afternoon while driving - Had alternator tested "Bad" - Replaced alternator.
2. 1 week later battery was dead one morning - Had battery tested "Weak" - replaced battery
3. 2 days later new battery was dead one morning, charged battery (1 hour) car started no problem.
4. 2 days later (after sitting not driven) battery dead again - not even a tick, no dash lights what-so-ever. Charged battery again.
5. Inspected vehicle; I hear no fan or other noises after car has been turned off for 20 minutes.
6. Tested battery for drain. Seems to drain .6V with car and all systems off.
7. Removed 1 fuse at a time to identify where the drain is coming from -Does not seem to be linked to a fuse.

Question? I have no idea where to go from here to diagnose the issue.

All/Any direction or suggestions are most appreciated.

Thnx All!

[4reagan]

Originally Posted by trader4

IDK what "seems to drain .6V" means. You need to measure the current
draw with the car in sleep mode, which would be 30 mins or so after
it's turned off and left undisturbed. The spec is for 35ma max. Mine
draws about 2x that, but still not enough to worry about. If yours is
more, then you need to pull fuses until you find the circuit.

Prime candidates are the FSR for the heater blower and the aux fan.

Until you get it fixed, I'd keep a battery tender on it so that the new
battery isn't being discharged all the time. Each discharge shortens
it's life.

Thanks very much for the reply!
Yes the car was in sleep mode when I tested the draw at the battery. I pulled every fuse and the draw was constant at 60ma.

I've had similar issues with E46's and the FSR but I could always hear the blower running - I sat in the car and listened and even put a stethoscope on the dash, there were no noises.

I'm just not sure where to even look or how to diagnose this issue.

Thnx for your advice. Cheers!

[omodos]

after 15mins mine sleeps, and the draw is down to 50mA , but got it down to this after pulling out fuses until i hit upon a culprit that was causing a higher drain it was rear dc socket in the boot......also when i did some research many said the problem i had on my 3.0D was a faulty started motor draining too much amps on starting and eventually draining the battery , not sure at all if this is the case (although amp drain test showed it is high) , temps have jumped up and since that time and the time i removed the fuses that now disabled the draining dc socket in the rear, i don't have this slow crank issue anymore

[4reagan]

Originally Posted by trader4

Apparently the drain, if there is one, wasn't there when you tested it.
I'd keep trying, as it may be intermittent. What is the voltage when
the car is running? Should be 13 - 14V. I'd check that, because the
other possibility is that the new alternator isn't charging the battery.

You're right that sometimes you can hear the FSR trying to move
the blower, just barely. But I think you can also have it fail with
a drain and you won't hear anything. Probably depends on how
much current it's sending the motor in failure mode.

Great Suggestion.
I checked the voltage at the battery with the vehicle running. At idle (about 600rpms) it was pushing about 12.25V, at operating speed (2000 rpms) it was pushing 13.75V).

There must be a draw. I'm going to try pulling the FSR fuse and letting it sit for a couple days - I'll update. Thanks!