Wired up a Garmin G5 with the wrong shielded cable and it drifted 3 degrees in 20 minutes
Used some leftover RG58 from a radio install instead of the spec'd twisted pair and after 20 minutes of run time the heading was off by 3 degrees so now I gotta pull the panel again and redo it right, anyone else ever chase a ghost like this and waste a whole weekend?
Laid out all my tools on the tarmac like a surgeon about to operate then realized I'd used the wrong wire and needed to start over. That three degree drift just stares at you on the runway knowing you'll be pulling the panel again. Bet your plane felt real smug about that one for the rest of the weekend.
Honestly, "Bet your plane felt real smug" is exactly the vibe, a buddy of mine did almost the same thing with a G5 in his Mooney and swore the avionics guy was messing with him until he saw the RG58 too.