I found a electrical plug that is not plugged into anything it is located behind the raditor cap under the turbo supply pipe to the intercooler. The plug is blue and no place for it to plug in that i can locate. Thanks for your assistance.

 

If it is a light blue/royel blue plug and is also on the same "arm" are the air pump plug then it is for the elelctronic EGR

 

On non-California '93 FD's it's supposed to be unplugged. Like c00lduke said, it's for the EGR (Exhaust Gas Recycler), which is located on the turbo side of the LIM (Lower Intake Manifold) where the charge elbow and y-pipe connect.