Darwinfish owns a Nissan Pathfinder with an electronic power antenna. He got tired of repairing it after rain leaked in, puddled in the gearbox, then froze. His solution is brilliant in its simplicity, a spring loaded beer bottle cap that covers the antenna opening when the antenna is down, then pops up when the antenna extends.
There is a steel spring from a wind-up car bent up to push the cap down over the hold when the antenna is down, and a bracket bent out of aluminum wire that holds the cap and spring together, and which is epoxied to the antenna housing. There is some fiddly detail to this project, like snipping and bending around a piece of the cap to form the hinge, and making the small clip he used to hold the spring to the bracket. Be sure to watch the video on the first page of the Instructable.
One comment suggested that it would be simpler to just epoxy the cap to the top of the antenna so it covers the hole when the antenna is retracted, but I agree with another commenter who said that there is a steampunkish aspect to this project that is very appealing.
One thing I’d do differently is not bend the hinge out of the ridged edge of the of cap, but instead get a small diameter section of brass tubing from the hobby store, epoxy that to the cap, and run the hinge wire through it. I also wouldn’t bother with the small metal clips that attach the spring to the bracket, I think some epoxy would make that simpler as well.
As the Darwinfish notes, the great thing about using a bottle cap is that you can almost certainly find one that complements the color of your car!
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