try a vocational or trade schools auto mechanics books, they are usually good with helping.
It should be on the fuse panel cover, but if not you can find it in a Chilton or Haynes manual, witch can be purchased from most auto parts stores.
Try Google
You can find a layout for the fuse panel of a 1990 Toronado Trofeo in the owner's manual. You can also find it at certain auto stores.
find someone that has a shop that has mitchell on demand.
take the kick panel off on the passenger side and you will find it there
Try the internet
I'n the owners manual
Haynes manual
Bottom of dash on drivers side.It has a cover on it and should be marked FUSE PANEL onit.
A person can visit a Ford dealership and ask for a 1989 Ford Bronco fuel diagram. Many times the Ford dealers will have mechanics on hand and they can give a customer a copy.
It is in the owners manual and you can get one from MOTORLIT.COM.
You can find the fuse box diagram, for your 1989 Ford Bronco, by taking the fuse box cover off. The diagram of the fuses is on the bottom of the cover.