Pro tip: Check the ground before you blame the box

I was troubleshooting a comms issue on a King Air last week, the VHF radio kept cutting out. I spent a good hour chasing it through the system, checking connections and power at the radio itself. Everything looked fine at the unit, so I was about to call it a bad LRU and start the paperwork. My lead, who's been doing this since the 90s, just looked at me and said, 'Did you actually check the antenna ground?' I hadn't. Sure enough, the ground strap from the antenna base to the airframe was corroded and barely making contact. Cleaned it up, problem gone. I learned that the issue isn't always at the expensive black box you're staring at. It's often the simple, boring stuff you skip because it seems too obvious. Anyone have a good method for checking those ground paths quickly without pulling half the interior panels?

2 comments

2 Comments

spencer19918d ago

Heard a guy say a cheap multimeter on continuity check is your best friend for that.

evannelson18d ago

Oh man, that's a classic. @spencer199 is totally right, a basic multimeter on beep mode is the go-to. I got burned once on a nav light that kept popping breakers. I was ready to replace the whole harness. My buddy just touched one probe to the light housing and the other to a clean bolt, got no beep. The ground path was shot right at the base. Saved me a ton of time and a stupid mistake. Now I always check continuity from the component ground to the airframe before I even open the book.