Liftgate problem (tape switch)
 

I have folllowing problem, when I push the remote and /or the button in the car it will open the liftgate but it's no possible to close it. I must than only manually. An electrician has said, according to computer it's going on: tape switch, which is constantly closed, instead of most likely on. Have anyone an idea. Where can I find this tape swich? Is it possible, that I can't close my liftgate. Thanks