Your camera will be twenty-three years old this year, it's outlived it's design life by around sixteen years.
If you're lucky, it just needs a thorough CLA service (Clean, Lubricate, Adjust) but the big question is the AF system: like ALL older AF systems, they're complex and spares are as rare as fresh dodo eggs. SLR';s should ideally be CLA'd every couple of years or so (sooner if heavily used), but in reality most never get done. As a result the lubricants applied in the factory eventually dry out and gum up the works and it's possible that this is all that's happened to your camera.
By all means consider getting a CLA done and also a one off foam light seal replacement for many more years of use, but be prepared to have to revert to good old fashioned manual focussing. The light seals are a worthwhile job as they'll be turning to corrosive sticky goo by now and modern materials don't degrade in that fashion.
Yours is a truly great classic camera and I sincerely hope that you mange to restore it to a usable condition. If you're in the UK then I highly recommend
Colchester Camera Repair; although they're an authorised Canon service centre they should have the skills and experience to work on your camera as well.