That wiring diagram struggle is so real. I mean, the manual pointed me to the general area, but it was still a total needle in a haystack. Was there one specific page or diagram that finally made sense, or did you just brute force check every single wire?
What part of the manual finally clicked for you? I spent a whole weekend once chasing a gremlin in my old truck's dash lights. The factory wiring diagram was basically a spaghetti map drawn by a toddler. I ended up just checking every connection on the dimmer switch first, which of course was the actual problem. Sometimes the manual gives you the path, but you still have to guess which turn to take.