Battery Drain Problem - BMW Forum

Carbarns · 08-25-2004, 03:32 PM

I'd be behold'n to any of your expert advice on the basic first steps to isolate a very slow battery drain problem. ('87 325)

Right now there are no obvious things like lights left on.

Thanks for the help in advance.

witeshark · 08-25-2004, 08:14 PM

Is there an alarm? Has the radio been rewired to by pass ignition switch? :wink

Old_School_Bimmer · 08-26-2004, 10:29 AM

i Had a simular problem but it turns out i had bad ground i am not sure if that would drain the battery but it would effect the starting of teh car

Carbarns · 08-26-2004, 10:36 AM

No alarms other than the ABS light coming on after starting. What I'm looking for is whether I need to do step by step pulling of fuses, using a voltmeter, etc.

Bear · 08-26-2004, 12:15 PM

Disconnect the negative battery lead from the battery. Take a ammeter (I use a multi meter) and hook it up between the negative battery cable clamp and the negative battery post. If you see mre than about 200ma, start removing and replacing fuses (one at a time) until the current draw drops and you now have located the offending system. I would continue the drill using all fuses to be sure there is not more than one system over drawing current.

Carbarns · 08-26-2004, 12:55 PM

Fantastic Bear!

I'm sure this type of info will help others besides me. Once I identify the offending fuse/systems what are the next logical steps?

BMW Lover · 08-26-2004, 04:23 PM

check the fuses with ... fuk i 4got wat its called...it has a lgith in side of it and looks liek a screwdriver with a really pointy tip and it has a ground wire comming off it...hmm ill try and get the name of the tool

gotKRAUT · 08-26-2004, 04:24 PM

Quote:

Originally posted by Slvr E30iS@Aug 26 2004, 05:03 PM
check the fuses with ... fuk i 4got wat its called...it has a lgith in side of it and looks liek a screwdriver with a really pointy tip and it has a ground wire comming off it...hmm ill try and get the name of the tool

um you pull the fuse and look at it...you can tell if its blown HOMESLICE lol and its an Ohm meter BTW i doubt fuses have anything to do with this but its worth a shot

BMW Lover · 08-26-2004, 04:32 PM

it works :-/

Carbarns · 08-26-2004, 04:39 PM

Yes, the fuses themselves are fine. It's the systems the fuse serves is the problem.

I'm really looking for the next steps to isolate the exact device causing the drain (fan, light, tach,...)

gotKRAUT · 08-26-2004, 04:42 PM

Quote:

Originally posted by Carbarns@Aug 26 2004, 05:19 PM
Yes, the fuses themselves are fine. It's the systems the fuse serves is the problem.

I'm really looking for the next steps to isolate the exact device causing the drain (fan, light, tach,...)

yup thats the next step i would go for