If I look at the schematic again, I see
- Two Blue yellow wires ( one to the interior light, and one to the personal light)
- One Red/wht wire going down to the dashboard warning light
- One Red/yel wire going to the door switches
- One white/blk wire going to ground
These colors seem to match up with your photo with the exception that we can't see any black markings on the white wire (perhaps there is a black stripe that we can't see on the photo) . Also according to the schematic the white/Blk wire attaches to ground near the left side of the roof, and may not run down the A-pillar at all.
Based on this information I believe that the 2 blue/yellow wires that you see, are the wires in question. You can prove this without cutting any wires by using a pin to pierce the insulation, and then measure the resistance from the wire in the pillar to the blue/yellow wire in either of the two lamp housings.
After proving that these are the correct blue/yellow wires, I suggest you look for a convenient place to cut the two wires. This could be below the dash, or in the pillar. You will then connect the two wires coming from the roof to a new wire which in turn will connect to a fuse which is hot all the time. You can do this using fuse taps to avoid the need to cut and splice any additional wires.
You could temporarily touch this new wire to a 12V source like the cigar lighter to prove it will work before spending any time or money to purchase the fuse taps.
I would still suggest trying to wiggle the connectors on the junction box which may clean any corrosion causing the bad connection.