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That moment my multimeter showed OL on a critical circuit

Was troubleshooting a navigation light fault on a King Air last Tuesday, and when I checked for continuity on the wire bundle, my Fluke just showed OL. Turns out a chafed wire had grounded out behind the panel, took me 45 minutes to find it. Anyone else have a simple thing like that eat up your whole afternoon?
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3 Comments
victor_robinson
And that OL just stares at you like it's mocking you, right? I swear half the time with avionics the real problem isn't even the broken part, it's the 45 minutes of poking around trying to find the one little spot where insulation just gave up. Had a similar deal on a 172 where a single pinched wire in a bundle caused an intermittent flap position light failure. Spent almost two hours pulling panels before I found it, just a tiny rub mark hidden behind a cable clamp. Makes you wonder if the engineers who design these panels ever actually have to fix them in the field.
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thomas_torres
thomas_torres1mo agoMost Upvoted
Right, that "known issue" file is probably just collecting dust in some engineer's inbox while we're out here inventing new curse words. There's nothing like a single chafed wire behind a cable clamp to make you question the life choices of the folks who laid out that harness.
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laura_schmidt82
Wonder if the design engineers ever actually sit in a cramped back shop with a multimeter cussing under their breath for an hour. Do they even get feedback on the nightmare they create, or does it just get buried in some "known issue" file nobody reads?
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