Hi, I want to thank everyone who answered my post. I tried most of the ideas presented to me. The information provided about the heavy positive battery cable, under the passenger compartment floorboard was right on. I did apply power to the trunk lock using a battery charger, however it did not work. I swapped to a 12 volt battery, still did not work. I then searched the engine compartment near and around the fuse box. Never did locate a lug/terminal used for jump starting. Finally I called MB Road assistance, the tech went straight to the passenger floorboard and applied power, no luck. He then went to the rt rear fuse box and jumpered the central locking system, no luck. Using a jump box and jumper wire to a box under the rear seat, the trunk finally opened. He worked on the car for over three hours before getting the trunk to open. He even said there is no lug/terminal in the engine compartment for jump starting. All the ideas presented were viable and probably would have worked, if my battery negative lead was not disconnected in the trunk. Again, thanks for your input.