99' C43 - Battery removed, now I can't access the trunk.
Thread Starter
Junior Member
Joined: Jul 2022
Posts: 22
Likes: 3
1999 C43 AMG
99' C43 - Battery removed, now I can't access the trunk.
Hello. So the battery died (premature failure, only 14 months old on a 30 month warranty batt) and I opened the trunk no problem 2 days ago with the key.
I have the new battery and tried opening the boot this evening, no go.
This vehicle has a push-in boot release w\hardware key.
Appreciate any support you can offer.
I have the new battery and tried opening the boot this evening, no go.
This vehicle has a push-in boot release w\hardware key.
Appreciate any support you can offer.
Thread Starter
Junior Member
Joined: Jul 2022
Posts: 22
Likes: 3
1999 C43 AMG
For whomever might read this, I used the positive wire junction under the hood + ground with a fresh battery and jumper cables to get the trunk open.
Replaced the battery and it started with no issue.
I'd still like to know why the boot wouldn't open with the key as it did 2 days ago.
Replaced the battery and it started with no issue.
I'd still like to know why the boot wouldn't open with the key as it did 2 days ago.
Senior Member
Joined: Jun 2019
Posts: 459
Likes: 65
C43 AMG with a tune up
Trunk locks are often seized and won't unlock with key?
People are lazy only using remote to open, I bet your lock wasn't used for many years and grime entered the cylinder!
What you can do is to spray penetrating oil into the cylinder and let it workt hen use the flat key getting jiggy with the cylinder.
You can use a flat plier for leverage but do it carefully.
Don't use brute force or you might break the key.
Dealership sells small protective dustcaps you can push into the locks on the drivers door and trunk lock.
Never close trunk with the battery removed.
You vwere lucky to have the positive terminal in the engine room so you could get power.
Trunklocks are always neglected when you need to access trunk key won't unlock.
You have to push the key IN and turn the key to unlock.
People are lazy only using remote to open, I bet your lock wasn't used for many years and grime entered the cylinder!
What you can do is to spray penetrating oil into the cylinder and let it workt hen use the flat key getting jiggy with the cylinder.
You can use a flat plier for leverage but do it carefully.
Don't use brute force or you might break the key.
Dealership sells small protective dustcaps you can push into the locks on the drivers door and trunk lock.
Never close trunk with the battery removed.
You vwere lucky to have the positive terminal in the engine room so you could get power.
Trunklocks are always neglected when you need to access trunk key won't unlock.
You have to push the key IN and turn the key to unlock.
Last edited by MattCordell; Jul 14, 2022 at 05:04 AM.
MBWorld Fanatic!
Joined: Mar 2010
Posts: 5,891
Likes: 323
From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
For whomever might read this, I used the positive wire junction under the hood + ground with a fresh battery and jumper cables to get the trunk open.
Replaced the battery and it started with no issue.
I'd still like to know why the boot wouldn't open with the key as it did 2 days ago.
Replaced the battery and it started with no issue.
I'd still like to know why the boot wouldn't open with the key as it did 2 days ago.
MBWorld Fanatic!
Joined: Mar 2005
Posts: 2,418
Likes: 194
From: America
1999 C43 AMG, 2005 E55 Wagon
This is the main reason they left a simple point under the hood to access 12v directly to battery and all basic systems; in case your battery is dead or removed you can simply provide 12v here and operate the car's systems.
