Honda Repair: Block heater cord plug, dielectric grease, wd 40

Question
Hello: I have a 2010 Civic EX-L,but this question is not really model specific.I live in an area that gets snow and cold in winter,and of course,I have a block heater.One thing that bugs me is that the plug for the block heater gets corroded pretty quickly,even with a cover on it.Would it be advisable to use something like WD-40 on the plug prongs to keep them from getting corroded,or can you suggest a better way of protecting the plug? Thanks!

Answer
There isn't quite enough info here to give me enough insight into this problem to really give the best answer I could. I'll go with what I have.
The first thing I would do is try to determine the source of the corrosion. If it is from things like road grime then I would try to seal up the plug better. It could be from all the work of conducting electricity (the same reason battery terminals corrode). If the problem is from electricity there are several things I would try. First I would try putting some dielectric grease on them. This ensures a good connection from the plug to the chord. You could also try using some anti corrosion spray or something similar (this is the same thing used on battery connections) and that would probably prevent it.

I hope this has helped.