Transit MK6 Driver’s door Door contact Lock problem PIN Occupancy?

Hello, I have the problem with my transit MK6 (12.2006) that more and more often when the driver door is closed, it is indicated in the instrument cluster that the door is still open. In summer it happens more often than in winter. When it is closed it is of course acknowledged by horns and the car remains open. After some research I have read that “flooding of the lock with WD40 etc. should help. I tried it, but does not bring anything. The contact is probably directly in the driver lock and is defective. I don’t want to renew the lock, first of all it works perfectly (except for the contact) and I don’t think it makes sense. I would like to close the contact now, so that the car is made to believe that the door is always closed (that doesn’t bother the light). So would I need the PIN occupancy from the plug in the door or? Or if someone has a manual or tips on how to reach the lock or possibly repair it. Is it also a cable break? But then it would NEVER close or? Thank you very much.