Electrical things that suddenly cut on/off make you wonder about connections (loose, or partially unplugged) or skinned wires rubbing against metal (shake the harness). When several things start doing it that can be a common ground point, or the fuse, or the wire connections for same. There are very few things more annoying and hard to track down than a once in a while electrical issue. I've even had fuses with a hairline crack in them. They have a mind of their own.