I'm making up an alarm unit in a plastic splash proof box. I've a 12V battery pack inside. I want to drill a hole and put a jack socket on the side of the box. I'm looking for a standard jack socket with that I can put a cover over afterwards to stop dust, water etc. going into it. Does anyone know where I would find one of these.
More aboutpower jack socket cover
Try Radio Shack.
And I'd suggest putting the jack on the bottom of the box. That way the box will do most of the sheltering.