Appreciation post: Finally traced a stubborn intermittent ground fault after 3 shifts

Ngl, I spent almost 12 hours over three days tracking down a ground fault on a 737 that kept popping up and then disappearing. Turned out it was a chafed wire behind a panel in the aft cargo bay, hidden under a bundle of other lines. I almost gave up and called it a ghost, but my lead told me to check one more spot. Has anyone else had a fault that took way longer than it should have to find?

3 comments

3 Comments

janab8218d ago

Oh man, I feel your pain. Had a similar nightmare on a CRJ a few years back where an intermittent light would flicker on and off for a week before we finally found a pinched wire under a floor panel that someone must have stepped on just wrong enough to make contact sometimes. It was one of those that makes you question your sanity.

jamiekim18d ago

Ha, yeah, I read somewhere that those CRJ issues are legendary for being hard to track down. Some guy on a forum said his buddy spent three days chasing a ghost light on a 200, only to find it was a single strand of wire barely touching a screw head. Makes you wonder how many of those things are just waiting to drive the next guy nuts.

paige_ellis5918d ago

Totally agree with @janab82 about floor panels being the HIDDEN culprits. What worked for me was going back to the SIMPLEST stuff first: grab a multimeter and start wiggling every connector and wire bundle in the suspect area while watching the circuit. Found a corroded pin on a relay block once that only showed up when I jiggled it at a certain angle. That ghost light on the 200 guys talk about? Bet it's the same kind of deal where a micro-fracture in a wire does the exact same thing. Patience and some good old fashioned wiggling beats any computer test every time.