What kind of wiring diagram are you looking for? Engine, radio, lights etc.
A wiring diagram will make sure that everything is connected correctly. The wiring diagram for a 1992 Buick Skylark can be found in either of its manuals.
ebay
next to the floor
I am looking for a wiring diagram of a direction signal or flasher for a 1992 E150 Ford Van.
You can find free wiring diagrams at www.autozone.com.
Contact an International dealership
you can usually find what you are looking for at carstereohelp.com
the electrical diagram is in the book... buy a service manual or a chilton's book
WIRING DIAGRAMS TOYOTA WIRING DIAGRAMS TOYOTA
Contact an International dealership
I found a wiring diagram in the factory service manuals at my local library.
Autozone website, DIY section, electrical