The Cessna 120-140 Association Forum

Does anybody have the Grimes Retractable Landing light maintenance and/or parts manual? I've run into a snag where I unscrewed one of the screws on the side of the lamp casing and the bulb dropped so now the screw just slides in the hole assuming the screw hole on the bulb doesn't match with the hole on the outside casing. I'm trying how to fix that? The reason I did it was for some reason the landing light doesn't work. The motor is working. I believe they are on separate fuses but all fuses are good. Since the light has a high draw does the light only work when the alternator is running (engine running)?

If you have the manual can you scan it and email it to me?

Thayne Inman
tdinman@msn.com

Can you post a picture? I'm not visualizing a screw into the lamp... The bulb is held in place by a giant snap ring.

You may have separate fuses for the lamp and the motor but there is no logic to prevent the lamp from coming on if the engine is not running.

https://cessna120140.com/wp-content/upl ... anding.pdf

There are some schematics in this pdf that might help you. Some pics from your end may help us.

Thank you for the information.

"Can you post a picture? I'm not visualizing a screw into the lamp... The bulb is held in place by a giant snap ring.

You may have separate fuses for the lamp and the motor but there is no logic to prevent the lamp from coming on if the engine is not running.
John Cooper"

I will send pictures today or tomorrow. Thank you.

I fixed the screw problem by taking the bulb out of the casing and found the back side of screw had a nut which had come off and fell into the casing. That screw holds a bracket that spring loads the light bulb against the retainer ring. So I put the nut back on the screw and put the bulb back in the casing. So that problem is solved.
Now back to why my landing light doesn’t work. All the fuses are good, the bulb appears to be good and besides I checked with a multimeter if I was getting power to the bulb when I had the bulb out and it seems to indicate no power when the landing light switch is on. So any suggestions people?

First I would get a jumper wire and test that the bulb is working.

Then check to make sure that power is getting though the switch.

Then the wiring itself to make sure the circuit is complete. Power is getting from the switch to the bulb.

Rick

There are 3 switches inside the motor housing, an up limit, a down limit, and a bulb on (when the light is down.)

6643 wrote: ↑Thu May 21, 2020 9:58 pm There are 3 switches inside the motor housing, an up limit, a down limit, and a bulb on (when the light is down.)

So there is a limit switch that allow the bulb to come on when the light is fully down?
Thanks John

8342 wrote: ↑Thu May 21, 2020 6:46 pm First I would get a jumper wire and test that the bulb is working.

Then check to make sure that power is getting though the switch.

Then the wiring itself to make sure the circuit is complete. Power is getting from the switch to the bulb.

Rick

I will check the following wiring to see if the above may be the problem.

Thanks Rick

Thayne