Peugeot 407 door contact signal faulty

Hey, I had a similar problem with my previous car, though it wasn't a Peugeot. Could be a faulty cable or connection somewhere in the door. Have you checked the wiring harness that goes into the door? Maybe a plug came loose?

Thanks for the tip! Where exactly should I be looking for this wiring harness? Is it something I can easily access myself, or do I need special tools?

Well, usually it's behind the door panel, where the door latch mechanism is. If you are unsure, I'd suggest getting it checked at a workshop. It could be more than just a loose cable and you might end up causing more damage. The door latch itself could be defective, too.

Thanks for your help! I took it to a workshop as you suggested. Turns out it was indeed a defective plug connection in the door. Cost me 95€ to get it sorted. Appreciate the advice!