Old timer told me to trust my tin whiskers during harness layup

I used to think tin whiskers on crimp terminals were mostly cosmetic until a 20 year tech at Lockheed Martin showed me how a single strand bridging two pins caused an intermittent fault on a C-130 nav system last month. He was right. Has anyone else had a false continuity reading from a whisker you couldn't even see?

3 comments

3 Comments

kevin2181d ago

Respectfully, I see whiskers hiding in the fan-out area just as often as anywhere else.

kevin2181d ago

Check the backshell strain relief too, I've seen whiskers hide right where the wires fan out.

miles5811d ago

Actually, tin whiskers don't usually hide in that exact spot inside the backshell. Usually they grow from the metal surface itself, and they can bridge over to the pins or the shield. I've seen them more in the crimp barrel area where the wire meets the contact, or along the braid where it's been cut. The fan-out point is worth checking, but in my experience the real trouble is further back toward the termination. Just something to keep in mind before you dig around in there.