Results 1 to 6 of 6

Thread: 1990 E32 Mystery Drain

                  
   
  1. #1
    Junior Member
    Join Date
    May 2011
    Location
    Fairfax Station
    Posts
    6

    1990 E32 Mystery Drain

    Need help finding what's draining my battery after sitting ~ 3 hours. Here is what I have done so far:
    1. Alternator checked and is charging
    2. New Battery
    3. Multimeter check - pulled all fuses and no drop in amps.

    Suggestions on what to do next..

  2. #2
    Senior Member John in VA's Avatar
    Join Date
    Jan 2005
    Location
    Leesburg
    Posts
    1,052
    Is the glove box or trunk light staying on?
    John in VA

    '74 2002tii
    '85 535i
    '86 535i
    '00 328i
    '02 325xi
    '03 530i
    '06 330ci ZHP
    '15 228i M Sport

  3. #3
    Junior Member
    Join Date
    May 2011
    Location
    Fairfax Station
    Posts
    6
    Nope.

  4. #4
    Junior Member
    Join Date
    Oct 2009
    Location
    Montgomery Village, MD
    Posts
    17
    I've been thinking about this for a day now. I have an '89 E32 735iA and also have to chase down electrical gremlins from time to time. Draining the battery in three hours should be easy to find (duh) so we're missing some clue or evidence. Did you try measureing the voltage across all the fuses? My thought is that maybe one is hot with the key removed when it shouldn't be receiving power. All of the power the relays receive are fused so it can't be those. What receives power but isn't fused? Maybe the cable to the starter or alternator? Maybe the starter solenoid is not quite turning itself off and letting power drain. A modest trickle wouldn't turn the flywheel, but would drain the battery pretty quickly. It's a straw to grasp at, anyway. Good luck.
    Greg Rea
    1985 M639 (arctic blue shark II)
    1989 E32/M30 (white whale)
    ex-1965 Ford Falcon Futura Convertible (302 H.O. auto, still in the family)
    ex-1986 E24 turbo (arctic blue shark I, sold 3/07)

  5. #5
    Junior Member
    Join Date
    May 2011
    Location
    Fairfax Station
    Posts
    6
    Thanks for the suggestions. I will check cables, i.e. battery, starter, alternator. She still has the original starter, so I may just repalce the starter before it goes out at the worst possible time. I am also planning on bringing her to the next DIY (at Russell BMW iI believe) for some hands on help.

  6. #6
    Junior Member
    Join Date
    Nov 2005
    Location
    Silver Spring
    Posts
    3

    Bad main relay?

    I had an 88 735i 5 speed just sold it. Had it for 12 years only drain problems was when I first purchased it took to dealer turned to be a bad or wrong main rely which was not turning off when the car was turrning off. I think it was draining in a week or less. Clarence

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Mystery Vanishing Coolant
    By Jenson Button in forum Do It Yourself
    Replies: 8
    Last Post: 04-24-2009, 12:00 PM
  2. 1990 BMW 325is
    By classifieds mgr in forum Classifieds Section
    Replies: 0
    Last Post: 05-21-2008, 11:54 AM
  3. DIY: Z4 Convertable top drain claening
    By JC5 in forum Do It Yourself
    Replies: 0
    Last Post: 10-27-2007, 10:52 AM
  4. mystery connector...
    By gnhovis in forum Do It Yourself
    Replies: 7
    Last Post: 09-07-2006, 09:29 PM
  5. E30 Mystery Part - Help
    By SharkD in forum Do It Yourself
    Replies: 4
    Last Post: 12-23-2005, 02:00 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •