In your car manual
The best place is to purchase a Haynes or Chilton's repair manual.
Do you mean a SCHEMATIC diagram?
You can find a vacuum diagram, for your 1992 Ford F1 50 pickup truck, at most Ford dealerships. You can also find the diagram at most auto-parts stores.
The Chilton's Repair Manuals has decent body part diagrams.
You can find a 1981 Ford F150 manual transmission diagram inside the vehicle's owner's manual. Some auto stores also have the diagram available.
Autozone
if you dont have the owners man. your local ford dealer will give you a copy just visit the parts counter
Where can you find a audio wiring diagram for a 1994 Ford F150?
where can I find a free diagram of dirt bike parts
You can find a full illustration diagram for a 93 Ford F150 automatic locking hub in the truck's owner's manual. You can also find it at various auto stores.
When making changes to any part of a car, a diagram will help the person know what to do. A diagram for a 1995 Ford F150 front suspension can be found in the maintenance manual of the car.
front brake assembly diagram for a 2006 F150 4X4