Can installing a battery mess up electrical system?

Remotes have to be re programmed.

The bcm has to re learn systems for the locks etc. Try removing the cable again, re installing it and then driving the car for a bit to see if anything comes back.

Roy

Just to add to this one that car doesnt have a body control module. The S model saturn didnt use a body control module till 2000 model year. Sounds like you have a bad door lock switch inside the car. Most likely the one on the drivers side door. Compare the passenger side to the drivers side switch what happens is the spring in the switch breaks and the switch doesnt return the center position. That causes the switch to stay in the lock or unlock position overheating the door actuators. Thats why they go crazy. Try unpluging the drivers door lock switch let the actuators cool down and see if the work. Lets start there let me know what you find.