Tracked a phantom GPS flag on a King Air for 3 days and it turned out to be a $2 connector pin
The GPS would drop out for like 2 seconds on every other flight, and me and two other guys pulled the rack, swapped the antenna, and reran half the coax over 3 days trying to chase it down. Turned out one pin in the J connector behind the panel was backing out just enough to lose contact under vibration, and a 10 cent crimp fixed what we'd been chasing with a $4,000 loaner unit. Anyone else ever burn days on a wire issue that a wiggle test would've caught in 5 minutes?
Man, the connector was behind the panel, so a wiggle test from the front would not have caught it anyway. You have to get hands on the harness itself, and a pin backing out only under vibration means it looks fine sitting still on the ground. Sounds like it took three days because it was a sneaky one, not because anyone skipped a basic step.