I have separate amber, stop, and normal lights. I'm having trouble finding the brake and normal lights in this circuit. I found left and right turn as they pulse. However, the yellow wire actually goes off when I press the brake pedal. The blue and black always seem to on even when I take the ignition key out. Any ideas how to troubleshoot? V70 trailer wiring https://imgur.com/gallery/ECyyZw2

the car lights are working correctly so something seems odd when probing the wires. Is it possible for a wire to go off like a relay is controlling it somehow? I would have expected that when depressing the pedal or indicating for the wire to suddenly have power in it.