Right turn signal in rear is not working. Replaced bulb but didn't help and fuse is good. Any ideas as to what is going on?

This is just a starting point. Remove the bulb and turn the blinker on, checking to insure the front blinker is in fact working. Use a 12vdc test probe to see if you have power to the socket. Ground you tester to the car and probe both contacts, one should show 12 vdc alternating. If one contact shows power then more to the next step. Move your probe to just the two contacts in the socket to insure you not only have power but also have a ground. If either contact is bad you probably have a bad wire leading to the socket and you'll need to trace that open line down.

Many years of ford exp... after checking above it is the multifuntion switch... better known as the multi*uckedup switch