Re: BMW 2003 - Best way of checking current draw? # Archived Message
Posted by John kennard on February 24, 2009, 3:25 pm, in reply to "Re: BMW 2003 - Best way of checking current draw? #"
Hi Terry, I have expensive low amps clamps but you cannot beat a physical amps reading at source, Amps clamps fluctuate all over the place for all sorts of reasons. Like the post above me just take your digital Volt/Amp meter most good meters go to 20 amps, remember to change the lead into the amps outlet, and always span between the battery earth cable and battery. So as you have access to the fuse/relay box in car disconnect the drivers door courtesy light switch or tape down, also remember to throw the door catch as many are monitored by micro switches in the lock assy for alarm systems etc. also if bonnet is open look for switches often built into the bonnet catch and close the switches. After approx 20 Min's on a modern car you should have max .01a-.001a possibly .000 if above just keep pulling fuses & relays till you get a significant drop. Common drains are Alternators, BMW as mentioned the heater module also 5 series had a run of faulty boot catches which didn't allow the system to go to sleep, a problem when left at airports and car was locked by the boot guaranteed to come back to a flat battery. Common are HR.Window relays removable radio faces also very common causing the radio to drain the battery these are but a few of the myriad of problems for current draw. John Kennard.
|
|