Good Day,
The Ignitin Lock  is coming with four wires, these are going to:

RED: Power from Battery via Main Fuse (Pos. over the Battery) ; In "ON" = Power to the Wire Harness
BROWN: technical Ground (Wire Harness internal)  not to missunderstanding with B for Black this is direct minus ( Frame, Battery minus)
BLUE: (for Light-System) leads forward to the Plug of Fuse-Box (10A Fuse)
RED / BLUE: (for Light-System) leads forward to the Plug of Fuse-Box, here the Color of the Wire will change into Blue and
                   it is coming out as Blue Wire from the Fuse Box and lead Power to the the right Handle-Bar-Switch, where the different Illumination
                   Option can be taken.

Remark: From Right Handelbar-Switch it is connected direct to the left Handle-Bar-Switch for Chose "LO" or "HI" Beam, and "PASS"

Trouble hooting Headlights:
a) Bulb OK?
b) No Cracks in the different Wires?
c) Is ther some corrosion inside the Plugs connectiing elements?
d) Check the Ignition switch it self ==> See the Picture do have Contact with a Pieper if you are set the Ignition Switch in on of the
    corresponding positions?
e) anywhere , check for good connectivity, if neccessary , clean it
f) check for cracks in wires. therfore switch your system on , with Batterie Power, and bend a little bit the wires around your headlight
    if there are some effects, repair it.
g) There are some selfmade modifications around the power coming from the Ignition Switch Wire? Perhaps new installed accessories?
    ( additional Lights: Fog-Lights, Day-Lights (LED) .and so on..)

So far with distance diagnostics

With kind regards
Anja