You can find a front door latch assembly diagram, for your 1996, Mercury Cougar from the manufacturer website. Many auto-parts websites will have the diagram.
You will find all O2 sensors threaded into the exhaust system at various points.
find a chilton manual, they are cheap
You can view the 1999 Mercury Cougar owners manual online at : www . motorcraft service . com ( no spaces ) Click on Owner Guides ( the fuses and relays section starts on page 152 )
You can get a vacuum diagram for a 1994 Mercury Cougar 4.6 liter in the Chilton's manual for that year and model. You can also find the diagram online at All Data DIY and at Engine Guy online.
http://www.cougarpartscatalog.com/1919mecovaac.html
there is a diagram sticker in the glove box for the fuses under the searing wheel
You can find a power steering diagram for a 1999 Mercury Sable in the owner's manual. You can also find it at certain auto part stores.
call the dealership they can print one out for you!
1999 mercury tracer fuse panel diagram
The Haynes Repair Manuals would have a diagram of the serpentine belt on a 94 Mercury Cougar XR7. You can find the manual at your local library, book store, or most auto parts stores.
You can find this information from John Sherbit-MOTOR MANUAL/MOTORALLDATA Distributor