Grimes landing light not retracting

[seberggelet]

Hello,

refreshing this thread. Running into the same problem with Grimes light stuck down and not clear in my understanding of the mechanism to retract it. The motor works, the light works. Just not sure how the mechanism works to get a current to the middle terminal of the motor. Any help is much appreciated. Pictures below.

[6643]

The switch on the panel selects up or down. Also, the up limit switch has to be closed (it is normally closed) for the motor to run in the up direction. If the limit switch contacts are dirty the motor won't run.

[seberggelet]

Thanks John,

can you talk me through that? How does the up circuit get actuated? Just switching the polarity on the wires as the switch would do, does not engage the motor in the opposite direction and I cleaned and checked all the contact.

[6597]

In the members/resources section on the Home Page I posted a Grimes Overhaul Manual years ago that shows the various wiring diagrams for several of the 3602 series landing lights, pages 16-18 or so. May or may not be useful.

https://www.cessna120140.com/Forum2018/ ... f=10&t=130 if you don't already have this Neal article

[wings]

The retractable Grimes landing light became included in my pre-landing checklist for my C170.

I operated the light on downwind before every landing to keep parts freed up and corrosion and crud on contacts and brushes at least minimized.

I never had a repeat problem after I started.