Avionics troubleshooting method I used for 10 years was completely backwards

I always started with the wiring diagrams when diagnosing a comm radio issue, spending maybe 45 minutes tracing circuits. Last month a senior guy at my hangar in Tucson watched me for a bit and said 'why don't you just swap the unit first?' Took me 3 minutes to pull the box from the rack and install a known good one, and sure enough the problem followed the unit. I felt like a total idiot for wasting all that time over the years. Has anyone else been doing something a certain way forever and found out there's a way faster method?

3 comments

3 Comments

ward.jamie27d ago

Did you ever try the 'swap and check' trick on something like a transponder? I spent years rebuilding carburetors before a buddy showed me just pinging the float bowl with a screwdriver handle clears most needle valve sticks in 5 seconds.

taraanderson27d ago

ward.jamie, did swapping the radio ever fail to find the problem?

eva_adams6827d ago

Wait, pinging the float bowl with a screwdriver handle clears stuck needle valves? That's wild, I have never heard of that trick in my life." @taraanderson I gotta say, that sounds almost too good to be true but I bet it works because those old carburetors were finicky as heck. I'm still stuck on the transponder swap thing though, I thought that was the go-to move for finding electrical gremlins.