When you had Honda install your factory trailer wiring kit, they should have left you with the included Honda sub-harness kit to splice to your brake controller wiring. That Honda sub-harness includes instructions to install a 20-amp fuse for the brake controller, and that fuse was also included with the Honda trailer wiring kit. The harness they should have left with you is shown in this earlier post:For sure, make sure you have a 20 low profile minifuse to get power to the brake controller port. I got a 2019 Passport. Had Honda install the factory tow kit, just to be sure. Found the BC port, plugged in the correct harness for Honda and my Tekonsha P3. Dark. I couldn't figure out why the BC port wasn't hot. This is my 4th tow vehicle, never encountered that before. I went to the dealer, said I wanted them to check and see why the port wasn't powered. Guy didn't tell me anything, said it'd be next week and anyway, brake controllers are aftermarket so they don't really deal with them anyway. Only after checking the forums did I discover a fuse has to be added (Honda doesn't provide it) to power up the port. I get it, but for over $1k to Honda installing the tow kit they should figure trailer brakes might be a thing and stick a 50cent fuse in the block, or inform the customer to make sure to do that. The service writer told me "well, most people pay to have that done by someone else so it gets done". Honda service disappoints me too often.