Interesting that your key does not unlock the door. I have a 2004 and the key will lock and unlock the door no problems without power and I have the central locking pump removed.

 

I can open my door on my 2004 with the central locking fuse #26 removed.
There are obviously contacts in the lock assembly that actuate the central locking pump when the key is turned but the driver door is opened when using the key with the central locking system disabled.
I doubt that 2004's are different so there may be a problem with the lock in the OP's car. The problem being that the lock cylinder is not connected to the lock mechanism.
Naturally Chuck Norris would have no problem with locks anyway, two suitably placed packs of plastic explosive would have the whole door off before you had time to dial a locksmith.

 

Okay, I got into the car by using Toolman's photo of the 2 bolts holding down the hood latch (thanks). You have to have a ratchet wrench or you could spend literally hours trying to do it otherwise. It took a couple of minutes and up comes the hood! After I put the charger to it I open and closed the driver door with the key with no problem. Anyway, I'm going to run a wire from the battery to just inside the front grille with an insulator cap on it. Then, if for some reason in the future I need to put juice to the car and can't lget the hood up, I'm all set!

 

But can you open the car door with the fuse #26 out? That is the big question, if you can then there is no need for the wire, let us know the answer. Inquiring minds .....
If you cannot why not?

 

If I can't open the door with fuse #26 out I'll not know why? If it is supposed to work differently than it does, then I'll get the car to the dealer and let them fix it - under warranty! I'll try and get time to get that checked tomorrow and then let you know!

 

Being a curious George I went out to test mine... my hood is always up in the the garage(so the mice wont build a nest on the SC) so I pulled fuse #26. Damn the fob dosent work any more.... but the car does pick it up as I can hear it clicking trying to open the doors. Insert key and turn, driver door unlocks fine. It does not unlock the passenger door or hatch.
With the fuse in and using the key it does unlock everything....

So it seems that the OP does have another problem if his key will not unlock the door...

 

That's what I have been getting at, the lock tumbler must have a part on it that connects to the lock assembly, just like the ones in the house doors. If that part is missing or not connecting the key will turn and do nothing as his does now.
I have not studied this part so this is just my guess. I could not see MB designing a car with such an obvious fault, so that's why I checked my car.
Turning the key normally operates the central locking system, with no fuse #26 the system is inoperative.

 

So what's the answer to this riddle of yours?

 

One quick point to think of... If you let your battery drain down to almost nothing, I would consider a new battery! Sulfation may have occured during the deep discharge and your battery may be damaged. I wouldn't risk a discharged battery, seeing as I cannot carry that OE/BE wrench in my pocket all the time. That was a GREAT FIND, that wrench access! Just a thought!

 

Mike, I pull out the #26fuse and then put it back. My keyfob still does not work at all! Now im totally kept out of my car because the battery is also dead! any advice?

Tian

 

Friend, you are quoting an old post from MikeR ( Rest in Peace ) who is only with us in spirit, but no longer in body.

 

Tian - you might want to look into the process of removing the hood latch as explained in an earlier post in this thread. That may be the only way to access your battery if your key won't open the door. Although, it was mentioned that a locksmith had the car open in just a few seconds, so that might be an option but make sure the locksmith knows what he is doing and doesn't set off the side airbag (per Doc's warning).

RL

 

Sorry, im a freshmen here. Sorry for mentioning MikeR that i dont know what happened to him. I didnt mean to it. So sorry about it...

 

Can't speak for the others.. but seeing his post referenced.. his work..etc.. doesn't hurt my feelings. I see it as "he still lives on in this forum".. as he always will.

 

^^^ THIS ^^^

The fact that it stirs something in us to see him quoted, that it makes us miss him all over again... testifies to who he was. And who he still is, to us.

 

Hi Guys

Just a quick line to say thank you for the information on how to get the hood (bonnet) open.

As suggested it took a little patience but I managed without causing damage to anything.

I cleaned the mechanism and reseated cable and all is well.

Great support guys and again thank you

 

This same situation just happened to me. I haven't driven my car in well over a month and I went out to my garage to move it so I could put some unused dressers behind my car but hold and behold, neither fob would open it. I knew it wasn't the batteries in the fobs given that both of them worked fine a little over a month ago and the likelihood of the batteries in BOTH fobs dying at the same time seemed slim to none. So I then tried to unlock the car the old fashion way but apparently something is wrong with the locking mechanism itself considering I could turn the key both directions but the car would not unlock. Who knows how long it's been like that - this is the first time in over 4 years of having the car that I have ever tried to unlock the car with the key itself. Going to try to unbolt the hood latch and see if I can get in that way. Wish me luck!

 

With the battery disconnected my key would open or lock the drivers door. Nothing else opened or locked.

 

Thankfully a good friend of mine had a lockout kit so we were able to get it open fairly easily.

 

You can remove the cylinder from the door and see if it is able to operate the door locking mechanism. I would guess that the tumbler is lacking the part on its rear that engages with the inner mechanism.
Look in the service manual for details.