The fuse contacts have burned up. Same thing happened to us (same fuse, same
model/year). I had to move the fuse, which entailed pulling the fuse / relay
assembly out (fairly easy - release the tabs at the side... I think the
radio has to come out though). I don't recall the position I moved it to,
but there weren't a lot of candidates. I think I cut and spliced the wire,
but it has been a while. I recall it wasn't a big job.
If you need to know which position I used, I can look tomorrow.
Mike