W211 E500 When the open button is pressed the trunk lid opens half way and stops. The red light on the trunk lid edge goes off at the same time. The lid can then be opened manually the rest of the way, but since the red closing assist light is off it also has to be closed manually. The trunk illumination light stopped working at the same time that this problem started. I looked but couldn't find a fuse box in the trunk. It seems that it should be something really simple, but you can never tell.

This is my sister's car and I don't know much about it. Any clues? Thanks.