Map light circuit. 1976 P337
 

So. Just recently got plane back from annual. The map light breaker keeps popping. Even when nothing other than the master is on.


They did two things during annual that may be the issue. PTT switch in pilots yoke and new oxygen generators. Both are very close to the lighting in overheard and on yoke. Any other ideas? I pulled all of the post lights thinking that might isolate the issue. But cannot track down the other items.

Map Light circuit.
 

So, after a lot of time, confirmed the issue was two of the three transistors that control the Electroilluminescient Lighting. The transistors are cheap, the labor, well no so much. Once again however I need to tip my hat to the team at Superior Aero based at KEXX. Fair and fast. Richard is a solid guy.