My 2003 expedition makes a buzzing sound in the fuse box when the temp is below approx 32. The ignition won't crang at all when this happens. I could push on the fuse box and it would start but now I have to heat up the fuse box with a hair dryer to get it to crank. Any suggestions.

 

Sounds like a bad connection inside the fuse box or connector, since heat makes stuff expand, I would lean towards this.