Automatic Trunk Closure Problem

[EmDee]

The auto-closing trunk mechanism on my W140 Chassis 93 SEL500 isn't working any more. The trunk will close and stay shut, but gone is the ability to lightly close it, and then have the mechanism slowly suck it all the way shut.

I got in there thinking the electric motor went bad or something only to find out there is no electric motor, all pneumatically operated. I did find one little switch in the setup that I'm thinking may have gone bad. All the other doors work with the auto-shut function so I don't think the pneumatic vaccum/compressor system is failing which is why I think it may be the switch.

Can anybody confirm that the switch would be causing the problem or that maybe its something else with a history of problems?