It would help if you could tell us what the lights are coming on. That is a start.

A): Check the terminals, maybe one is loose from a sloppy mechanic. It happened before.

B): How old is the battery?

C): What does the battery read with the car running? Do this if you know what you are doing.

D): Whatever you do, don't let anyone tell you to throw parts at it yet without some basic troubleshooting for a good idea of what the problem at hand is.

Report back with your findings. I am just guessing, I haven't touched a 1995 S320 before.