I have recently purchased a 94 e500 that has been sitting for about 4 years. I have the master key, it is a factory square key.
The key will work the locks and ignition however it will not turn in the trunk lock. Need to get into the trunk to replace battery.
I know there is a method to power up the car in the engine bay but I do not know exactly where to connect power. Any help would be greatly appreciated.