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Old timer at the avionics shop told me to stop trusting the pinout diagrams
I was wiring up a new GPS antenna on a King Air 350 last week and kept getting a null signal on the test set. The pinout chart from the manufacturer showed pin 4 as the coax center, but this crusty old guy named Dave who's been doing avionics since the 70s saw me struggling and said 'that chart is wrong, swap pins 4 and 5.' I almost ignored him because the diagram was printed right there, but I figured what the hell, I'd try it. Swapped the pins and bam, signal came through clear as day. Turns out the revision on that installation manual was from 2019 and they never updated it after a harness change. Now I double check every pin with a continuity tester before I even look at the chart. Has anyone else run into bogus documentation from the OEM on newer installs?
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margareto2622d ago
Oh, you bet I've seen that kind of garbage from OEMs more times than I can count. Avionics manuals are written by people who never actually touch the hardware, I swear. That Dave sounds like a real gem, your mileage may vary but those old timers have seen so many revisions and undocumented fixes it's scary. The worst is when a diagram is just flat out wrong for years and nobody catches it because everyone just follows the chart blindly. A continuity tester is now my best friend too, takes five seconds to save hours of headache.
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lewis.terry22d ago
Hannah asking if the OEM knows yet, that's a good one lol. They know, but they'll pretend they don't until someone files a safety report or it causes a real problem. That's pretty much how most of these "revision 12" manuals get made, someone finally screams loud enough about the wrong diagram. Old Dave probably has a whole notebook of stuff the OEM claims doesn't exist, but he just shrugs and fixes it anyway. Continuity tester for the win though, never trust the paper, trust the wire.
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