X5 E70 Brake Lights Fault

[Muzimak]

Hey guys, I have a weird problem here, my left tail light, Stage 1 Brake-Light works well, stage 2 on top is dead. Right tail light stage 2 works, stage 1 dead (Vice-Versa), I swapped the bulbs around both side, problem remain, so it's not bulbs. After a lot of Youtube research I tried everything from Sand Paper on connectors to Contact Spray still no luck.

I asked my wife to go into the car and step on the brakes, I disconnected the left main harness, put it back in, the dead stage 2 light went on, 6 seconds later it switches off, tried several times same thing, the right tail light nothing happens by doing this.

Could it be a Fuse? Will running diagnosis help at all? Please help!