I had a rat or a squirrel chew up some vaccum hoses and electrical wiring, does any know where on the internet I can get a vaccum hose schematic for a 2006 F-350 ????

You might try here.

http://www.fordforum.com/forum/

How can I keep em out from under the hood of my truck?

A pellet gun would be fun.

moth balls will deter them a little bit.

Set out some traps and bait. Seen what they can do to a brand new car sitting on a lot, not pretty and this one ended up being a total loss.

Does any one know where I can find a schematic for the vacuum hose on a F-350 ? I can not find it on the internet

Try the Ford forums, I posted a link previously. Here is another one, ask these guys are usually very helpful.

http://www.f150online.com/forums/f-250-super-duty-diesel-38/

Call your local dealership. They should be able to print out a schematic for you. Usually no charge.