why does fuse blow when I try to adjust the drivers power seat ?
Possibly a short in the wire connector under the seat or in the wiring itself, as it can come into close proximity to moving parts. A short would blow the fuse, the problem may be in the motor too. If you have a digital multimeter you can use that to check the continuity of the wiring and see if there are any shorts. See an older topic on this type of problem: http://www.cargurus.com/Cars/Discussion-t41910_ds571213
Search Saturn L-Series Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Saturn L-Series Experts