Keyfob
 

My key fob quit working so I replaced the battery and it still doesn't work. Do they have to be reprogram, and if so does anyone have the instructions.

Which vehicle are you asking about?

2007 exp Eddie Bauer

See page 112 in the attached link and see if it will help. Replacing the battery should NOT lose fob programming, but you might be able to fix it by following these instructions from the user manual. Also make sure the battery is not in backwards. Don't ask me how I know.;)

http://www.fordf150.net/2007/2007-fo...ers-manual.pdf

The programming is in the vehicle module.
the fob simply sends a coded signal to the vehicle.
The vehicle compares the code to it's recognized list.
From the owners manual;
Note: Replacement of the battery will not cause the remote transmitter
to become deprogrammed from your vehicle. The remote transmitter
should operate normally after battery replacement.

Programming remote transmitters
It is necessary to have all (maximum of six — original and/or new) of
your remote transmitters available prior to beginning this procedure. If
all remote entry transmitters are not present during the programming
procedure, the transmitters that are not present during programming will
no longer operate the vehicle. Note: Do not press the brake pedal
anytime during this sequencing, as doing so will invalidate the procedure.

Well it just started to work all of a sudden. It took like 3 days after I replaced the battery to work for some reason. Oh well. It's all good now

Key fob
 

I have a fob from a 03 Expedition could I reprogram and use it on my 07 Expedition?

As I understand things you can.
When I have a vehicle going to salvage I collect the fob for reuse.