I added a brake controller to my 2001 Monaco, I didnt go fancy with a higher end Tekonesha P2 or 3, I went with the voyager which is way more simplistic. I had to run a wire directly from the front of the bus to the 7 pin as there was none on the original chassis wiring. For power I found the front fuse bus and found the CB had a dedicated 20amp fuse. I rarely use the CB, and decided to tap its power and ground for the controller, worse case I know what fuse to replace in the panel below the drivers compartment.
For the brake signal, there was no signal under the dash due to the air over hydrolic setup as it used a pressure switch somewhere. But I found in the same fuse compartment the brake lights fuse and tapped it there after the fuse. So far after 3 years I have had no issues other then the 7.5 amp fuse installed for the brake lights would pop....after reading the wiring diagram for the chassis, it was supposed to be a 10amp, once I installed the 10amp fuse I have had no issues since.
2006 Ford F350 6.0
2014 Primetime Sanibel 3600
Enough other vehicles to not bother listing.
Previous RV: 2001 Monaco Knight