Originally Posted by wkerfoot
The yellow wire is from the brake controller to the electric brakes. The word stop on the brown and red wires means the brake lights.
Thanks for clarifying that. I'm now at a loss then. I get power at the 7 pin off the tow vehicles when I hit the brake. I get power from the 7 pin plug on the Airstream to the lights, and I get power from the fuse box to the lights. I'm going to retest from the 7 pin at the Airstream again because it did require a helper to tell me what was lighting up but I checked these myself from the fuse panel.
I still have the black wire from the umbilical going to the fuse panel that seems to do nothing when powered up. Since the yellow is for the backups on my system, do you think the black wire might be going to the brakes?