My 2004 Z4 the battery discharges in about 4 days if not run....Anyone know what is going on??? It's the 2.5i


Asked by Feb 10, 2014 at 08:26 PM about the 2004 BMW Z4 2.5i

Question type: Maintenance & Repair

1 Answer


Have the battery checked, if it tests good then check for a battery draw, disconnect the negative cable and put a test light in between the cable and post, if the light lights bright then there is a draw, first thing to check is the alternator, electrically disconnect it, if the light goes out then you have a bad alternator, most likely a diode went bad, if the light is still bright then you will have to remove the fuses 1 at a time until the light goes out, write down where each fuse goes as you remove them. Be aware that some vehicles have a parasitic load that will cause some test lights to just glow not a bright light that glow would be considered normal.

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