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Spent 4 hours chasing a wire that didn't exist
I was troubleshooting a no-radio power issue on a Cessna 172 last Wednesday. The schematic said there was a relay behind the instrument panel. I pulled the panel and spent 2 hours looking for it. Turns out the previous guy removed the relay and just hardwired the circuit. Another 2 hours wasted tracing wires that ended in nothing. Has anyone else run into phantom components that just aren't there anymore?
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patricia3213d ago
That's a classic headache... had that happen on an old Piper once where the previous owner had clipped out a voltage regulator and just twisted the wires together. Did you check if the relay was maybe relocated somewhere else like behind the glove box or under the co-pilot seat? Some mechanics get lazy and just hide stuff wherever it fits instead of following the manual. Wonder if your schematic was for a different year or model variant too, those Cessna diagrams can be out of date by a few revisions.
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lewis.brian13d ago
...and that's exactly the kind of thing that makes you want to pull your hair out, right? I've seen so many "field approved" fixes that turned into nightmares down the road. The schematic issue is real too - I swear Cessna changed things between model years more than they ever admitted in the manuals. You'd think they'd at least put a revision date on the damn thing so you know if you're looking at the right one.
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Oh MAN, that is the WORST feeling when you've been hunting something that doesn't even exist anymore. Had a similar thing on a Mooney last spring where the manual showed a circuit breaker that apparently got moved to some random panel under the pilot seat years ago. Spent a solid 3 hours rechecking every wire bundle and cursing the whole time. The previous owner's logic is ALWAYS a mystery, like they just decided "eh, this relay is extra weight" and spliced it without telling anyone. Those Cessna schematics are a JOKE sometimes too, I've found three different versions for the same plane model year and none of them matched the actual wiring.
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