Ground loop or bad wire? Still not sure what happened with that King Air last Tuesday

I was troubleshooting an intermittent comm drop on a King Air 200 in Nashville last week. Pilot said the #2 radio would cut out after 20 minutes airborne. Started with the antenna coax, looked clean. Then I found a 2 volt difference between the airframe ground and the radio tray ground. Re-ran the ground strap and tightened every screw I could find. Two test flights later and no issues. Anyone else ever had a radio issue that turned out to be a lazy ground bond instead of a bad box?

3 comments

3 Comments

wilson.sam17d ago

Two volt difference? Thats wild. Glad you caught it before swapping boxes.

shane65516d ago

Bring up a good point about checking under load @wilson.sam - was this reading you took at the panel or at the device itself? Could be some voltage drop happening through a bad splice that'd show up differently once you plug something in.

margaret_gonzalez2517d ago

Did you also check the ground wire before making that decision? I've seen cases where a difference like that comes from a bad connection on the neutral side, not the actual source. It's a good reminder to always double check with a meter under load, not just at rest. A couple volts can really mess with sensitive electronics if you aren't careful.