How to unlock a BMW with a dead battery

Jim Furlong

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?

Jim Furlong



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 out of 1 people think this is helpful.
Jim Furlong

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.

3 out of 3 people think this is helpful.

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

Jamal M.Zubaidi

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.

1 out of 1 people think this is 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

  • 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

  • Where are the battery terminals for 2003 BMW 525i? 1 answer

    My battery is dead due to being parked in garage ... I would like to try charging it, but can't find the battery terminals .... HELP

    2003 BMW 5 Series 525i


    Maintenance & Repair

  • how to open car when battery is dead 14 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 19,042 nationwide 5 Series listings starting at $1,500.


Search BMW 5 Series Questions

BMW 5 Series Experts

#1 Tom Demyan
Tom Demyan
Reputation 1,740
#2 Michael Branan
Michael Branan
Reputation 710
#3 Robert Charlson
Robert Charlson
Reputation 670
View All

Related Models For Sale

Used BMW 3 Series"
1,629 Great Deals out of 39,717 listings starting at $1,500
Used BMW 7 Series"
208 Great Deals out of 5,862 listings starting at $2,995
Used BMW 6 Series"
114 Great Deals out of 3,026 listings starting at $5,995
Used Honda Accord"
1,282 Great Deals out of 78,151 listings starting at $1,395
Used Dodge Charger"
671 Great Deals out of 30,154 listings starting at $1,995

Used Cars For Sale

2016 BMW 5 Series 535i For Sale
16 Great Deals out of 1,815 listings starting at $47,968
2015 BMW 5 Series 535i For Sale
70 listings starting at $32,499
2014 BMW 5 Series 535i For Sale
17 Great Deals out of 283 listings starting at $28,985
2013 BMW 5 Series 535i For Sale
39 Great Deals out of 423 listings starting at $19,900
2012 BMW 5 Series 535i For Sale
8 Great Deals out of 130 listings starting at $15,992