horn does not work
Check the fuse panel to see if the fuse has blown.
where is relay located
Don't forget to check and see if the lugs attaching the wires to the horns are corroded. Sequence is "Fuse; Horn ring contact inside 'horn push'; corrosion on lugs at the horns; then start looking foe open wires or the horns themselves can be corroded and the vibrator stuck. You'll need to disassemble and clean the horn mechanics or just buy new ones.
There is no actual "Fuse" for the horn. There is, however a relay. Having the same issue with my 1994 Sunbird.
Looking for a Used Sunbird in your area?
CarGurus has 11 nationwide Sunbird listings and the tools to find you a great deal.
Search Pontiac Sunbird Questions
Pontiac Sunbird Experts
Related Models For Sale
Used Cars For Sale