Unable to open doors due to disconnected battery

Hi all.

I just finished read the thread, while sitting near my car, and was unable to open the doors.

The car was parked for 2 weeks so I disconnected the battery, just in case.

Today I arrived and couldn't open the doors. Connected myself to the forum and tried all the tips on a thread posted a while ago.

Then I remembered that I left the negative cable way down and try to reach it from under. I was able to link a cable between that cable and a (-) from a donor car. NOTHING.

What now???

Tips, advices. Appreciate all the help.

Best regards

Hi all. One more thing.
I connected ground to another car and positive remains on mine.
I only disconnected groumd and my battery was ok.
I'm I missing something obvious???
Thanks and best regardd

I do not understand.
Are you able to gain entry to the vehicle but the doors remain locked?
Way down?

Typically, if the battery is completed disconnected (negative and positive), you have to manually lock each door.
I do this all of the time with my 92 M50.

Originally Posted by Bugsie

Hi all. One more thing.
I connected ground to another car and positive remains on mine.
I only disconnected groumd and my battery was ok.
I'm I missing something obvious???
Thanks and best regardd

Yes, you do not have a closed circuit. It has to be a circle. The positive in your car can now get OUT of your car to the next car THROUGH the negative, but cannot return to the positive on your car.

Charge does not travel both ways on one wire. Connect the positives.

Before that, just try the emergency door unlock procedure, but with the following difference. Try lifting the door handle WHILE you are turning the key and not before. See if that works. You may have to do that several times to get the right simultaneous combination working.

Hi all.

My car has the battery on the motor compartment and I simply disconnect the ground. I can reached it from under the car because the cable is hanging.

I tried that emergency procedure after reading a thread here but not working. I'll keep trying.

Again , I'll also try to find a hot connection from the battery, maybe the starter, and connect positive there and ground on the hanging cable.
Thanks Roberto. I also thought of that. Something was missing there and I couldn't get it right after a 8 hours flight.

I'll keep trying, thanks for the help.

Best regards

Hi all.

Done. After reading some threads, I just plugged a booster to the starter and ground it on the vehicle. Popped right away.

Thanks to all.

Best regards

Originally Posted by Bugsie

Hi all.

Done. After reading some threads, I just plugged a booster to the starter and ground it on the vehicle. Popped right away.

Thanks to all.

Best regards

You can do the same by plugging a 'booster' into the rear side markers...way easier.

Originally Posted by MeanM50

You can do the same by plugging a 'booster' into the rear side markers...way easier.

or the trunk light...

Originally Posted by paperplane94

or the trunk light...

Some people can't get to the trunk light...the marker light is ALWAYS available.

Originally Posted by MeanM50

Some people can't get to the trunk light...the marker light is ALWAYS available.

My sidemarkers are sooooo brittle its not even funny. The trunk doesn't need any electronics to open with the key.

Hi all.

The trunk didn't open with the key.

Sorry to ask, but what do you mean by marker??

For the two procedures, trunk and marker, the ground cable can be disconnected???

Thanks for those tips. I have to keep those in mind for the next time.

Best regards

Originally Posted by Bugsie

Hi all.

The trunk didn't open with the key.

Sorry to ask, but what do you mean by marker??

For the two procedures, trunk and marker, the ground cable can be disconnected???

Thanks for those tips. I have to keep those in mind for the next time.

Best regards

Sorry Bugs...euro cars don't have 'side markers'...they are little rectangular lights that the US cars have on their bumper trim...it's the white rectangle on the rear bumper in this pic:



YOUR bumper should have 'euro trim'...AKA-flat trim...no light...like this pic:



Now, I would wager that the harness for the rear side marker is present on your car...pop the trim off the bumper and look around for an unhooked light harness. The trick should work with no batt hooked up...all it does is feed the voltage through the system backwards so you can use the locks...it's the same thing as hooking a lead to the starter...but it's WAY easier to get to...

Good luck!

Trunk doesn't open manually with the key?
That's a first...
Something is wrong with it then.

Originally Posted by paperplane94

Trunk doesn't open manually with the key?
That's a first...
Something is wrong with it then.

Hmmm..... I was thinking that the actuator for the trunk is electrically powered ??? Is this not correct?

Hi all. Thank you so much for all the inputs.

And I believe so. The trunk lock is electrically powered.

Also, my car comes with LSD, lowered suspension and a few more features. As far as I researched, there was some special editions here in Portugal with those..

I'll look for that harness

Best regards

Originally Posted by BMR_LVR

Hmmm..... I was thinking that the actuator for the trunk is electrically powered ??? Is this not correct?

It IS electrically powered...but the mechanics are directly driven by the key...so it SHOULD work with the key EVERY time...but I have ran into a trunk that didn't open with they key...you will likely need a new trunk latch to fix the problem.

Originally Posted by Bugsie

Also, my car comes with LSD, lowered suspension and a few more features. As far as I researched, there was some special editions here in Portugal with those..

I'll look for that harness

Best regards

In the US, we didn't have the 525i 'sport'...because it featured all the options that came standard in the US (other than the LSD). We all got moonroofs, power windows and power leather seats standard...while EU markets had to 'option' leather seats and power windows etc...

Just noticed that Bentley has an emergency unlock procedure on pg. 515-2.
Has anyone tried this?

Due to a discharged battery, use the passenger side front door (additionally drivers side on pre 1990). Place key in lock and lift door handle while turning key fully in CW direction. Same to lock.

Originally Posted by My525iT

Just noticed that Bentley has an emergency unlock procedure on pg. 515-2.
Has anyone tried this?

Due to a discharged battery, use the passenger side front door (additionally drivers side on pre 1990). Place key in lock and lift door handle while turning key fully in CW direction. Same to lock.

It's not 100%...the mechanism that operates the 'emergency unlock procedure' can break very easily. I've had terrible luck in this department. Almost every E34 I've owned hasn't worked.

+1 with the trunk (boot) lock. It should have a rod attached to the lock at all times - mechanicial unlock. Check the owners hand book as to which way to turn the key. If the car did not come with one try e-bay. Worked for me.

Hi all.

Tried that "emergency opening" with no luck.

The key doesn't move on the lock neither way. I'll put that on the correction list. Stay tuned for a new thread after the compression test.

Here we have to "build" he car. For instance, mine as ZF box, LSD, lowered suspension, electric all around, two temperatures AC, pre-heating device, fabric seats...