Central locking not working on drivers door rest of doors working if i open pasenger door by inside door opener

My 93 Peugeot 405 Central Doors Lock not working neither Remote Key , nor Manual Key gets respond, no actuator sounds is heard when Key is inserted and turned but front doors are operated only manually (by Key), I checked all the Fuse i.e. #15 all were intact , I tried to check the Central Lock Relay I could not find its actual location how and where should I trace it? One more incident that interior ceiling light is also gone almost at the same time and not responding to Door Open-Close pilars bottom & inside direct On-Off switch , Does it mean of functional relation on both points? , Appreciate being guided how to approach DIY procedure? Tnks,

Renew the drivers door lock or check if the operating solonoid is seperate from lock if so then often a good drop of engine oil down the operating arm often works