What I used to do when I had the flat-type connector, was to use a little grease on the contacts, then slide a sandwich-size baggie over it and fasten it with a bread bag tie. The grease kept the contacts from corroding and the baggie kept all the crap out.
This is not the cheapest trick, but it's what I use. I bought a spare 'trailer' pigtail from the dealer and cut off the extra wire (better to keep the wire and simply tie it neatly to the side in case you ever need to use the plug). Naturally it plugs onto the truck pigtail abd provides a perfect seal. Quick and easy. If you want to really go crazy, buy a spare 'truck' pigtail and use it as a plug for the trailer. See ya,
Noel- I may have a spare 5 flat "trailer end" laying around. If I can put my hands on it tonight, you can have it. Use contact grease, and leave it plugged in just as Joe suggested. Either that or switch to the new large round connector. The truck end has a flapper door thingy that keeps the contacts clean.
What I use is simply a rubber hitch ball cover that comes with a flat bulge on the side the ball which stores the plug when the trailer is not hooked up. Its about $5 and the neatest little trick I know for the pigtail. Now, where to get it? Thought I purchased it from Northern Bass but do not see it in the currant catolog. But somebody sells it, and if you find out who does let me know and I'll get a spare.
how i do it..... lightly grease contacts....2 wraps of saran
wrap...2 wraps HD aluminum foil.......
use to use baggie's but found this to work better....and its cheap
both items you should have in your house already....
i like beacuse it stays tight to the wire.......it also easy to undo
as i have to use my dump trailer.....for work