1997 S430 Electric Door Lock Activation blows fuse 11 (20 amp) in trunk
 

This problem started suddenly four weeks ago when the trunk lid would not close for my wife after she opened it with the key fob. Turns out the body mounted latch for some reason closed after the trunk was opened. I released the latch and the trunk lid closed properly for a few days. Then the switch inside the car would not open the trunk. Found fuse number 11 in the trunk fuse compartment blown. Replaced the fuse and system worked fine for a few days. Then the trunk switch would not open trunk. Fuse was found to be blown again. Replaced the fuse. Found that when the trunk latch was manually closed with the trunk open, fuse 11 would blow. Replaced the fuse and manually closed the trunk. Chrome closing lever did not retract. When the trunk was opened with the key, fuse 11 again blew. With the trunk open, when the trunk lock key turned counter clockwise to release the lock, fuse 11 blows. When the trunk latch is manually closed with the trunk open, the vacuum closing system seems to work fine for the doors, however sounds like a capacitor in the computer on the left side of the trunk discharges at the end of the closing cycle. Fuse 11 also immediately blows.

If I close and lock all the doors manually then replace fuse 11, the fuse does not blow until I (a) either close the trunk or simulate closing the trunk by manually closing the trunk latch or (b) using the door key to open the driver's door (only door with key lock) or (c) using the key fob to unlock the doors.

I have disconnected the power to the locking mechanism on the trunk by removing the plastic trunk sill and unplugging the wiring harness on both the left and right sides.

Any thoughts on what is causing this. Obviously a dead short in the locking mechanism, but is there an easy to access relay somewhere that could cause this problem?

Been a great car for almost 20 years. Only 65,000 miles on it.

1997 Mercedes S 420 Door Locks
 

I am new to Peach Parts Mercedes Shop Forum. I made my first post on December 13, 2015 to which Nick responded with the question "when you close the trunk latch with a screw driver, does the fuse blow? I tried to respond by saying "Nick, yes the fuse blows when the trunk latch is closed with a screw driver. When I disconnect at the plug on the right (passenger side) back of the trunk connecting wires to the trunk light, the fuse does not below. However the fuse still blows if the key fob is used to lock the doors or trunk or if the passenger compartment door door lock switch (either unlock or lock) or the trunk open switch is pushed.

I cannot find where I made that response or if Nick further responded. I am sure I just do not know how to get to the right spot. Any direction will be appreciated.

Gordon