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

Add photo

Related Questions

  • Power off how do I pop the trunk? 6 answers

    My bmw egnition key wont Open my trunk , the car battery is dead so I can't unlock or pop the trunk. I tried the hole in the back seat but the hole is blocked to get to the pull cord. Is there a wa...

    2002 BMW 5 Series 525i


    Maintenance & Repair

  • how to unlock the trunk with the battery disconnected and key lock in the trunk 2 answers

    i accidentally left the key in the trunk while disconnect the battery . is there a way to unlock the trunk . Please help

    2000 BMW 5 Series 528i


    Maintenance & Repair

  • Replace battery in BMW and started having electrical problems immediatly 1 answer

    i have a 2008 BMW 538i. replace the battery and some of the elctrical system dont work such as car alarm front door lock and unlock and power mirrors. Is it true that i have to let the car go to sle...

    2008 BMW 5 Series 528i


    Maintenance & Repair

  • Battery Keeps Going Dead 2 answers

    My BMW slowly died the other day while driving. The way it slowed down, wipers started moving slowly and lights dimmed - I figured alternator and since I have a second car for parts (ran great just w...

    1985 BMW 5 Series


    Maintenance & Repair

  • how to open car when battery is dead 15 answers

    i cant open the car door. my battery is dead

    BMW 7 Series


    Maintenance & Repair

5 Series

Looking for a Used 5 Series in your area?

CarGurus has 15,988 nationwide 5 Series listings starting at $1,700.


Search BMW 5 Series Questions

BMW 5 Series Experts

#1 Tom Demyan
Tom Demyan
Reputation 2,040
#2 Michael Branan
Michael Branan
Reputation 780
#3 Robert Charlson
Robert Charlson
Reputation 690
View All

Related Models For Sale

Used BMW 3 Series
973 Great Deals out of 31,729 listings starting at $1,000
Used BMW 7 Series
188 Great Deals out of 6,134 listings starting at $2,999
Used BMW 6 Series
83 Great Deals out of 3,098 listings starting at $6,977
Used Honda Accord
813 Great Deals out of 84,287 listings starting at $1,050
Used Dodge Charger
407 Great Deals out of 28,172 listings starting at $1,988

Used Cars For Sale

2016 BMW 5 Series 535i For Sale
3 Great Deals out of 178 listings starting at $41,593
2015 BMW 5 Series 535i For Sale
4 Great Deals out of 79 listings starting at $28,500
2014 BMW 5 Series 535i For Sale
28 Great Deals out of 657 listings starting at $21,415

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.