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Finally got that stubborn autopilot fault on a King Air to clear

Three years ago at the regional airport in Billings, I first saw this weird intermittent fault on a King Air C90's autopilot. The system would just drop out for a second during climb, no hard codes, nothing. We swapped boxes, checked harnesses, the usual. Last month, the same plane came back with the same issue, and I was determined. I spent a full day last week with the manuals and a multimeter, tracing every inch of the pitch servo circuit. Turns out it was a single pin in a cannon plug at the servo itself, backing out just enough under vibration to break contact. A tiny bit of corrosion on it too. Crimped a new pin, sealed it up, and the test flight was perfect. It feels good to solve a puzzle that's been in the back of your mind for that long. Has anyone else had a ghost fault that turned out to be a simple connector issue after chasing it forever?
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4 Comments
emery_black
Totally get that, @the_joseph, those tiny gremlins are the worst to find.
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susan_wright34
Remember reading about a guy who chased a fuel gauge problem for weeks on a Seneca... turned out a spider had built a nest in the vent line for the tank, messing with the pressure. Makes you wonder what else is out there just waiting to be a headache. I bet @the_joseph has seen some weird ones like that too. It's crazy how the smallest thing, totally unrelated to the actual part, can cause such a big deal. Always feels like a win when you finally spot it though.
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craig.mila
Ever find yourself double-checking every connector now after a chase like that?
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the_joseph
Man, those connector gremlins are the worst.
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