The Cessna 120-140 Association Forum

Good evening,

I was out at the airport today and discovered another problem that I need some help on. When I did the prebuy, everything was working but tonight the retractable landing light came down and turned on but will not go back up. I checked all the fuses (I think). The light stays on continuously. I intended to replace the bulb with an LED but I couldn’t even figure out how to get the bulb out. Now it’s stuck down with no way to turn it off except the master switch. Any ideas?

Take a look at "Forum Archives" (below) and, there, @ a Neal Wright article on the Grimes Swing Down Landing Light. There'll be ops discussion and some diagram there. There's gotta be either a fuse or circuit breaker, probably 25A for the bulb and an additional lower amp for the motor. RE replacing the bulb, it can be a bear to get the old out and fit a new one in, even though the "modern" LEDs are made to same specs...requires taking the assembly out & getting it on the work bench for "leverage". Hope that'll help. Mac

There is a giant "circlip" holding the lamp in. Somewhere on the circumference you will find the two ends, with nubs. Squeeze the nubs together to compress the ring and remove it from the housing.

Be sure that the circle clip is not rusted or the nubs will break off when you try to squeeze them to remove the clip.

6277 wrote: ↑Tue Sep 01, 2020 6:53 am Be sure that the circle clip is not rusted or the nubs will break off when you try to squeeze them to remove the clip.

Good advice...don't ask how I know. Getting the old bulb out is relatively easy/simple, as is installing an original type glass bulb. Installing a new LED "plastic" bulb into the spring loaded assembly while reinserting the retainer clip requires some finesse and "talking to", 'though it will fit/function well once accomplished. Mac

Mac - I know how you know, I don't have to ask. I know the same thing.

Avlite has the circle clips and they are not cheap. I recall more than $50 last time I checked. Seems like a suitable sub could be found somewhere.

Well - mine now has one fewer tabs...turns out snap ring pliers work pretty well if you have a second fellow push the bulb in at the same time. Those tabs are kind of worthless. I still haven’t figured out why the motor won’t run the light back up. I have checked every fuse in the panel. Now I guess I need to get underneath and see if there’s a fuse that’s been added somewhere. I am hoping it’s not the motor itself.

Read the article. There are limit switches in the housing that often get oxidized contacts.

Here is one example of the limiter contacts. If you stare at it long enough you can figure it out. Contacts need to be cleaned, and may need adjusting. Wiring may need some TLC, you won't know till you open it up.