Warning: a bad crimp on a cannon plug in a King Air cost me half a day

I was working on a King Air 200 in Wichita last month, doing a routine transponder check. Everything looked good on the bench, but once I powered up the system, the thing just would not talk to the test set. Spent an hour checking the wiring diagrams, thinking it was a software thing. Finally, I pulled the cannon plug from the back of the unit, the big 55-pin one. One of the pins looked okay at first glance, but when I gave it a light tug with my needle nose, the whole wire just slid right out of the crimp. Someone had used the wrong tool, or just didn't set it right. Had to re-pin the whole connector, re-run the test, and of course it passed. Just a tiny, lazy mistake from whoever did the last install, and it ate up my whole morning. Anyone else get burned by a bad crimp that looked perfect?

2 comments

2 Comments

caseyfox13d ago

Had a Cessna 172 with a bad fuel gauge for weeks. Traced it to a pin in the nav light circuit. The crimp was so good it passed a wiggle test, but failed under vibration.

the_river13d ago

Yeah @caseyfox, I've had that happen with a bad crimp on a sensor wire too.