Grimes Landing Light - another repair adventure!

[Romeo Tango]

Other threads have discussed it, but it's worth repeating. Last week I had the dreaded "light comes down, won't go on, won't go back up" syndrome. Not a huge issue for me, just a bit of extra adverse yaw on the left. But I need about 25 hours of night time to wrap up my ATP, so it became a whole bunch more important to me!

So, I disassembled today and took it largely apart. What I found was the wire from the light contactor (the mechanical switch that engages when fully extended and provides 12V to the lamp) was frayed where it went throught the parabolic reflector of the light. There was a lot of contact resistance, and a low-grade short circuit. On further investigation I also found that most of the screws were oxidized, and a number of washers were missing. Worst - the bowl that seats the lamp has a hole drilled through it to allow ingress of the 12V cable. And that hole was never deburred, so it is basically a turret of razor blades happy to shred the old wiring insulation. Ack!

I can replace the insulators with some bakelite. I can replace the screws and washers and most wires. The one bit that is going to be a challenge is a contactor plate/wire assembly that goes from the contactor switch (fully extended power-on) to the lamp. I can hack together a welded assembly but would replace with new if available. A carcass aircraft would likely have the same age issues. I think this is the last ancient wiring in the airplane, and well due for replacement.

My AP/IA has no idea what is about to hit him tomorrow first-thing.

[GAHorn]

Whenever a wire passes thru any sheet-metal, it should have either a grommet or a sheath to prevent chafeing. Even a simple solution such as a short length of "heat-shrink" will work well to prevent chafeing-thru to a short.
Good luck finding the parts!