Put a new alternater in but battery still drains
Country: AustraliaMake: BmwModel: 318isYear: 2004
New alt new battery
Hello, I'm Jason.I will do my best to answer your question quickly and accurately using the information you have provided.Do you have a multimeter that will measure amperage, up to about 10A?
Ok, good. It sounds like you have a key-off battery draw, and here is what you need to do to narrow it down.1) remove positive battery cable from battery2) attach multimeter leads between cable and battery post.3) set meter to read amps, or milliamps, depending on the size of the drain4) open the door to get to the fuse panel5) make sure all doors and boot are either closed, or manually latched using a screwdriver, so that the interior lights are off and the car "thinks" everything is closed6) wait about 5 minutes7) record the reading on your meter.8) start removing fuses one by one, until the amp draw reading drops significantly9) find out what components are on that circuit, as it's one of those causing the draw.10) unplug any components on that circuit, and there is your offending part11) once you get down to 40-50mA, you're within range of normal
20 years of experience working with BMW's. Independent European shop owner and technician.