Fought a bad ground on a Citation for hours yesterday

I was working on a Citation 560 in a hangar in Wichita last night. The right nav light was flickering and the radio would cut out on the same side. Ran my continuity checks three times and everything looked fine but it kept acting up. Finally I just pulled the connector apart and saw a tiny bit of corrosion on one pin that I missed the first two looks. Cleaned it with a little contact cleaner and re-seated it, problem went away. Has anyone else spent way too long chasing a ground that was just a dirty pin?

4 comments

4 Comments

rodriguez.felix2mo ago

Funny how that works, same thing happens with old car stereos and weird computer issues. The tiniest bit of grime or oxidation can break a circuit that looks perfectly fine to the eye. Always worth hitting the pins with cleaner before you start tearing apart the whole harness.

david5621mo ago

Had a buddy who fixed his whole furnace by just cleaning the flame sensor with a dollar bill. @rodriguez.felix is right, sometimes the simplest fix is the one everyone overlooks. The electronics world is basically held together by good contact and a prayer.

brooke7672mo ago

Actually, continuity checks wouldn't always catch that particular kind of corrosion issue. A meter can show good continuity through a thin layer of oxidation since it uses such low voltage, but once current starts flowing through the real load it creates resistance. I've seen the same trick happen with poorly crimped terminals that test fine with a meter but fail under load.

alice891mo ago

Honestly I feel like everyone's making a bigger deal out of this than it really is. Dirty pins happen, you clean them and move on. It's not like you found a cracked wing spar or something actually dangerous. The 560 has like a dozen connectors under that panel and half of them get greasy from the mechanics handling them anyway. I've seen guys spend three days chasing a phantom ground on a King Air only to find out a wire nut was loose behind a panel that nobody thought to check. Sure it's annoying but it's part of the job, not some big mystery.