W202 C Class..Unable to gain access to Boot due to flat battery

Page may contain affiliate links. Please see terms for details.

Vlad

MB Enthusiast
Joined
May 30, 2003
Messages
2,411
Location
Reading, England
Car
Various Mercs come and go
How do I gain access to the Boot of a W202 C Class......its battery is so flat I had to enter the car using the skeleton key, however, it would appear that at some stage maybe the rear boot lock may have been changed as the skeleton key will not go into the lock and it only works on the drivers side door lock.

Naturally I need to get into the boot to gain access to the battery.

Question...is there a way to start the car with a Jumper Pack by attaching it to some live connections in the engine compartment??......I know that on a W210 E Class there is a "Live" terminal where you can connect a Jumper Pack, however this does not appear to be the case on a W202.

Any idea's?
 
There are always going to be live terminals in the fusebox- other wise the main supply terminal on the starter motor solenoid should do it. In the past mercs came with several keys some opened everything one only opened the boot some only opened the doors. The idea being you could lock the boot to safeguard luggage if access to other parts of the car were required for service. I think the skeleton key only opened the doors/ignition for that reason.
 
Last edited:
I had this on my 202, but it was fitted with the ski glove, so with that removed and a couple of broomstick handles, I did something to crack it open.
It has been a few years since I had a 202, but I seem to remember a terminal under a hinged plastic lid on top of one of the wheel arches, but cannot for the life of me pinpoint it for you.
You could jump start via the solenoid, but may I suggest that you make up a single cable that bolts onto the solenoid terminal first, giving you a flying lead well outside the engine area - the 202 may bea tad long in the tooth these days, but there are a lot of [expensive] electronics to go 'pop'...
 
This is the one Hal is talking about, put Live + to 2 or 3 and Negative - to a good earth on chassis and operate remote fob or switch on dash to open boot.

Dec

JumpLeads.jpg
 
Managed to open it....just got back and read the comments above and I kind of went along the lines of Hal and Dec

ie; popped open the plastic flap, connected the positive clamp from the jump pack to the middle lead (not easy due to size of clamp), ie No2 shown in the photo and then the negative clamp to the lifting eye on the engine.

Took care not to start the engine incase it fried the ECU, but by just putting the Jump Pack on it provided enough juice to power everything up and I could then open the boot with the key fob.

Cheers

Vlad
 
sorry to resurrect the thread but i have the exact same problem and i tried the method mentioned here but nothing, no power at all.

Does anyone have any ideas?
 
There was a guy who posted here recently how he went in through the First Aid Storage flap and opened the boot from the inside using one tool duct taped to another.
 
If the battery is flat then restoring power should normally allow you to operate the central locking unless there is a fault with the pneumatics or electrics- favourites are the vacuum pump under the offside rear seat or the cables at the boot hinge. Other possibility might be the supply to the convenience module under the nearside rear seat. Might be worth checking the under bonnet fuses and relay unit also.
 
IF you can get to the vacuum pump then I have seen the boot opening by some judicious vacuum being applied to the relevant pipe.
 
sorry to resurrect the thread but i have the exact same problem and i tried the method mentioned here but nothing, no power at all.

Does anyone have any ideas?

Are you SURE you are making a good contact at the Positive+ post and Negative- at a good clean unpainted part of the chassis… it should open with the key fob button or the boot switch on the dash.

Dec
 
Are you SURE you are making a good contact at the Positive+ post and Negative- at a good clean unpainted part of the chassis… it should open with the key fob button or the boot switch on the dash.

Dec

i was worried the battery might be completley dead. I'm going to try and get the boot open.
 
How do I gain access to the Boot of a W202 C Class......its battery is so flat I had to enter the car using the skeleton key, however, it would appear that at some stage maybe the rear boot lock may have been changed as the skeleton key will not go into the lock and it only works on the drivers side door lock.

Naturally I need to get into the boot to gain access to the battery.

Question...is there a way to start the car with a Jumper Pack by attaching it to some live connections in the engine compartment??......I know that on a W210 E Class there is a "Live" terminal where you can connect a Jumper Pack, however this does not appear to be the case on a W202.

Any idea's?

Sounds like you've managed to do it now, but i had this in the past with another car.
I made a lead which had a cigarette lighter plug on one end and a 12v drill battery on the other.
I turned on the ignition, plugged my lead in to the lighter socket and got all the electrics working. I'm not sure if this would work on the w202 with all the relays in circuit, but something to bare in mind next time.
 
i was worried the battery might be completley dead. I'm going to try and get the boot open.

Doesn’t matter if the battery is dead, if your key fob is good OR the switch on the dash is ok then you should get the boot open once power is applied as described………..all this assumes there is/was nothing wrong with the electric boot lock before you had this problem?

Dec
 
Doesn’t matter if the battery is dead, if your key fob is good OR the switch on the dash is ok then you should get the boot open once power is applied as described………..all this assumes there is/was nothing wrong with the electric boot lock before you had this problem?

Dec


it all worked perfectly before. could i charge it from the alternator?

Out of the wires in the picture above i don't have a wire connected to no-1, what is this wire for? I only have 2 and 3.
 
Last edited:
it all worked perfectly before. could i charge it from the alternator?

Of course, but how are you going to start the engine to get the alternator running?

This is one of these "I can't believe we are still talking about this" threads.
 
What are you using for your power supply Dave, a battery charger?

Dec
 
The Red Positive jump lead goes to 2 and 3…are yours the same as in my picture, that is are the joined together?
The black jump lead goes to any unpainted metal part that is part of the cars chassis.
When these 2 cables are connected then the key fob or switch should work provided the contact you are makeing is clean and not rusty.

A picture of your terminals might be useful if you can put one up.


Dec
 

Users who are viewing this thread

Back
Top Bottom