Odd electrical problems

I own a 1993 5 speed Saturn SL2 with around 150,000 miles, and have had problems with many of the electrical components since I bought it two years ago. The main problems are with the door locks and electric windows. For starters, the rear windows can be rolled down using either set of controls (front and rear), but can only be rolled up from the controls on the rear doors. The front passenger side window also does not always roll up, a problem that started 6 months after I bought the car. On occasion, the problem corrects itself and the windows operate normally for a minute or two. The driver side window is beginning to exhibit the same behavior, although a stripped gear in the mechanism prevents me from ever trying to use it. As far as the door locks, it blows any fuse as soon as I put one in. Again, on occasion, I have managed to get them to work momentarily during which time their operation is flawless, but it too lasts for only about a minute. I've been told these systems are operated by a computer rather than a simple relay-and-switch system, and thought perhaps that could be malfunctioning. I can understand how a broken switch or a short can cause these problems, but how do you explain its irregularity? The car itself runs smoothly. Any advice? Thanks.