How to unlock a BMW with a dead battery


Asked by Feb 16, 2015 at 01:31 PM about the 1984 BMW 5 Series 535i

Question type: Maintenance & Repair

My son has a 1984 535i that has been sitting a few months. The battery has died and the key will not unlock the door with no power. The windows are partially open, and we were able to reach in and pull up on the lock, but without power that won't work either. The AAA guy tried all the lock opening devices he had with no luck. We even tried hooking his battery to the tail lights. We were able to get interior lights to power up, but no enough power to make the locks work. I am at a complete loss as to how to get this car open so I can pop the hood and jump the battery.

6 Answers


The key doesn't unlock the lock in the door?

3 of 3 people found this helpful.



Will the key go into the lock cylinder but not turn? If that's the case get wd40 or PB Blaster and put the red straw into the cylinder and spray. Have a rag close by to wipe up the overflow. Now insert the key then take it out. Keep doing that over n over again then spray again. When you insert the keep trying to tutn the lock. At some point the lock will move. In might even take a day or so but it will move. Nobody uses a key in the door anymore because of the remote entry. So the lock doesn't get used and gets stuck. Last ditch would be call a mobile locksmith.

1 of 1 people found this helpful.

Key goes in the lock just fine, It turns just fine, but the lock is electronic and with a dead battery it will not unlock. The windows are partially open, and we even got an arm in the window, pulled up on the door lock but it would not unlock because it is electronic and the battery is dead.

6 of 6 people found this helpful.

Ahh I see. I would contact a BMW dealer or a European mechanic.

1 of 1 people found this helpful.

just put the key in the driver door side lock, and before you turn the key, left up the door handle and hold for few second and then turn the key left not clockwise and should unlock.

2 of 2 people found this helpful.

Your Answer

5 Series

Looking for a Used 5 Series in your area?

CarGurus has 16,246 nationwide 5 Series listings starting at $1,995.


BMW 5 Series Experts

  • #1
    Tom Demyan
  • #2
    Michael Branan
  • #3
    Robert Charlson
View All

Related Models For Sale

Used BMW 3 Series
1,113 Great Deals out of 32,630 listings starting at $1,000
Used BMW 7 Series
146 Great Deals out of 5,852 listings starting at $2,500
Used BMW 6 Series
88 Great Deals out of 2,688 listings starting at $5,700
Used Honda Accord
1,031 Great Deals out of 60,523 listings starting at $999
Used Dodge Charger
414 Great Deals out of 27,419 listings starting at $2,495

Used Cars For Sale

2016 BMW 5 Series 535i For Sale
78 listings starting at $35,840
2015 BMW 5 Series 535i For Sale
4 Great Deals out of 123 listings starting at $25,695
2014 BMW 5 Series 535i For Sale
34 Great Deals out of 601 listings starting at $20,920

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.