Had a weird intermittent fault on a Garmin G1000 autopilot trim servo last Thursday

The plane kept logging a trim fault only during climb, but the bench test showed nothing wrong. I finally found a tiny crack in a wire bundle near the actuator mount after wiggling everything for an hour. What's the most annoying intermittent fault you've had to chase down lately?

3 comments

3 Comments

faithwalker1mo ago

Oh man, a buddy of mine just spent three weekends on his old truck. It would randomly die at stop lights, then start right back up. No codes, nothing. He replaced the fuel pump, the relay, the whole deal. Turns out it was the wiring harness rubbing on the frame under the dash, just a single wire with the insulation worn through. The vibration from the engine at idle was enough to short it out. He said he almost sold the thing for parts.

xenagarcia1mo ago

Used to believe the weird intermittent stuff was the worst, but your buddy's story flipped that. At least a rubbed wire is a physical thing you can point to and say "there it is." The true nightmare is the phantom fix. Changed a coil pack on a friend's car for a misfire that only happened in the rain. It worked, but we never found a crack or any moisture. Just a part that decided to be moody. That kind of mystery leaves you feeling like you got lucky, not smart.

kim7271mo ago

Chasing those ghosts is the worst. Honestly, I don't find wiring faults that annoying anymore, they at least make sense. The real head-scratchers are the ones where you fix it and it just... stays fixed, with no clear reason. Like a radio that would cut out only over water, or a door sensor that failed on Tuesdays. You replace a dozen parts, and then it just works, and you never know why. That lack of closure drives me up a wall.