The corner of my living room (on split level) has drafts coming in via the bottom of the wall and a sump pump well (specifically, a plastic pipe that drains into it). The carpet is damp to the touch, and the carpet tacks are rusty, but there's no liquid water in the sump, even after heavy rain.
FWIW, the rain downpipe extends away a few feet from the house onto a slope (nevertheless, I'm thinking about digging a french drain outside in the spring).
What should I do to seal the corner (on a budget)? On the outside, is the air getting in through the brick? the siding? the porch? the ground? On the inside, is the sump actually doing anything useful? If not, would it be good or bad to cap it with airtight insulation?