Brief Description: Configuring Avionics—Problem with Transponder
Today I started downloading the latest software for all of the avionics which have updatable software so I could begin to configure my system with correct input/output formats. This was actually the first time I turned on all the equipment to make sure it worked, independent of my test bench testing prior to installation. As I was building harnesses, I tested all the wires end-to-end and turned everything ‘ON’ at the test bench but this was the first time I turned everything on after it was installed. Big bummer... the Transponder did not light up like it was supposed to. I started troubleshooting from the Master Avionics Switch, to the Transponder Circuit Breakers; checked all the grounds and didn’t find anything wrong. I rebuilt my test bench and connected the appropriate leads and everything worked like it was supposed to. Then I tested grounding and power leads in the harnesses. Still, everything worked as advertised. That’s when I realized Garmin mounted the male J7231 Connector on the Transponder upside-down from what the diagrams showed. This was different than all other Garmin products I installed on the airplane and when I mounted the female part of the harness I built to the rack assembly, I mounted it right-side-up like it should have been. The Transponder has a locking mechanism that should not have allowed me to slide the improperly mated connectors together, but there must have been enough ‘slop’ in the back of the rack that I didn’t notice the Transponder wasn’t aligned properly and it wasn’t flush with the panel face. Anyway, once I found the problem, I rotated the harness on the rack and VOILLA, it works!
