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Warning: A bad door zone sensor on a 2005 Kone MonoSpace took me three days to figure out
Got called for a car that wouldn't level right at a medical building. The door would open about two inches and then just stop. I checked the motor, the belts, the controller logs, everything I could think of. The problem was a tiny, almost invisible crack in the plastic housing of the door zone sensor, letting in moisture and giving a false signal. I spent two full days on the wrong stuff before I found it. Has anyone else had a sensor fail in a way that didn't show up in the standard diagnostics?
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jenniferchen6mo ago
Oh man, that "almost invisible crack" thing is the worst. My buddy had a similar headache with a parking gate arm that kept thinking it was hitting a car. He replaced the safety edge, checked the loop detector, the whole deal. Turns out the sun had baked the wire insulation on the photocell beam sensor, just enough for it to short out when it got hot in the afternoon. It tested fine in the cool morning, so it drove him nuts for a solid week.
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beth3126mo ago
Yeah that's a brutal one, @jenniferchen. I used to always blame the loop or the safety edge first on those ghost hits. Stories like your buddy's totally changed how I look at it now. The heat cycling on old wiring or a sensor is such a sneaky culprit. Makes you test everything at the wrong time of day and just chase your tail.
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