Suzuki swift booster jet rear door central locking issue

[den9112]

Hi, i have 2018 suzuki swift booster jet and i have just noticed that the rear passenger near side door is not locking via the remote (central locking) nor will it work with the key locking method ,same with the internal switch to lock and unlock while driving ,all other doors and boot work fine i also know the door worked on Jan 1st as i put a child seat in and used it and to be honest it's not been used until yesterday when i noticed the issue have taken the door card off and checked for any obvious loose wires also cleaned the multi plug that goes in to the door lock actuator and the problem is still there..I am not great with electrics so didn't want to start messing but i would like some help or advice on using a multimetre to try and eliminate any of the wires ...A shot of the multi plug wires