Emergency Unlock Question

[John B.]

The wife called from work today to tell me that she couldn't unlock the car. Turns out she left the lights on so the battery was dead. I ran her through the Emergency Unlock procedure but no joy. Tried it myself when I got there on both front doors but nothing happened. Original factory master key & my Ilco copy. I'm guessing that this is a mechanical unlock since there is no power?? If so how could it not work??

Ended up jacking up the car, crawling underneath & attaching the positive jumper cable side to the starter hot. This worked after I got a good ground on the tranny case. I'd prefer not to go through that again so any thoughts on why the emergency procedure wouldn't work would be appreciated as I'd like to get it working again.

[Dave M]

It has always been a tricky procedure on my 91 525. Many attempts to get the button up, but can usually manage it on the passenger side. An easier way to power to the door locks is via the license plate light or any wiring accessible inside the trunk.

Dave

[John B.]

An easier way to power to the door locks is via the license plate light or any wiring accessible inside the trunk.Dave

Depends where the car is parked. She parks in a lot & I had no way to bring power to the rear of the car. Also I only had jumper cables & didn't want to fry the wiring. This brings up the question of the trunk lock. She was able to get into the trunk so either the locks weren't synched or the trunk lock opens without power??

[mattyb]

passenger door, key in, hold handle up and turn key opposite to normal lock position. works every time for me; have a prob at the moment with 535i its a daily occurrence. its a matter of mucking about with it and getting used to the procedure. doesn't feel normal at first but practice with it for future. when I first tried it it didn't work and did my head in but a few goes later youll work it out. best of luck. regards MattyB

[whiskychaser]

Depends where the car is parked. She parks in a lot & I had no way to bring power to the rear of the car. Also I only had jumper cables & didn't want to fry the wiring. This brings up the question of the trunk lock. She was able to get into the trunk so either the locks weren't synched or the trunk lock opens without power??

I was never able to use the emergency opening procedure on my car so I'd advise you don't depend on it. Yes, you can always get in the trunk without power. At some stage, my car had a large ICE system and a PO kindly left the power cables. I just fed them into the trunk and made sure they didn't short. Ideal for opening the door. You could put another B+ terminal in there but that's probably a bit OTT:-)

[John B.]

mattyb - It wasn't an issue of not doing it correctly or it being fiddly there was just nothing happening at all on either door using the emergency procedure.

w/c- I was thinking about running a battery cable into the trunk & set up a covered terminal similar to what is under the hood. I have the cable w/lugs already.

[whiskychaser]

w/c- I was thinking about running a battery cable into the trunk & set up a covered terminal similar to what is under the hood. I have the cable w/lugs already.

The one under the hood is actually called the B+ terminal :-) You will need one for the ground too so maybe get a couple from a breakers.

[mattyb]

I hear ya there John, I didn't mean to be condescending, its seems every car has its own idea of how this is supposed to work. on the 535 when I did work it out I seem to have bent the lock arm that activates the lock and had to remove the door card to fix it all up. trunk / battery cable idea sounds better already.

[shogun]

There are several tiny plastic grommets in the link system. When they get old and brittle, they crack and fall out and then the links can also fall out or the exact length between the parts connected with the links is no more given. See for details the drawings on realoem dot com

In case your E34 has a trunk light, you can use the trunk light to power the system up enough to open the doors, trunk always opens with the key. Here is a write up:
The trunk always opens with the key, no matter if the battery is completely empty or there is no battery at all in the car.
Trunk light is best,this is what Tim once wrote:

unlocking doors via trunk light connections


The emergency unlock is known by lifting the passenger door handle and then turning the key over a certain resistance.
Even with a dead battery the trunk can be opened with the key by turning it anti-clockwise and then push the door unlock button.

To avoid wrong connection of power to the wires or to blow the fuse, Timm from the 7 series register in the U.K. has made a nice write-up:

A few pointers to connecting power to the boot/trunk lamp:

Firstly, the boot/trunk light is a good place to connect power as it is constantly connected to the battery via Fuse 33. However, you must only use a charger at this point, and only one that can supply a maximum of 10A. If you use a fully-charged battery you will blow Fuse 33.

The boot/trunk light has two wires going to it, RED/WHITE is the positive supply, connect the chargers +ve terminal to here. Connect the charger-ve lead to somewhere on the chassis.....this removes any possibility of reverse polarity.

When the charger is connected and charging, allow 10 minutes before trying the central locking, this is just enough time to get enough charge in the battery to supply the locks.

If you have not got a charger you can use a battery but MUST connect it via a 55W (headlamp) bulb. This reduces the current to a safe level.

DON'T connect to any other lighting point, these go via the LKM or General Module and it is not a good idea to stuff power up these!

[John B.]

I saw some of these ideas on the E34 website but it would be nice to have something dead simple that will work where ever you are without going home for a charger, ect. Not too many places to plug in a charger in a commuter parking lot.

One positive lug in the trunk, the jack stud mount should be fine for a ground, jumper cables & someone willing to let you hook up to their battery & provide a jump start.

As far as the door lock linkage I noticed that the doors unlocked in the Emergency Unlock position once their was power restored???