I have a 1999 ford f-250 5.4. I am trying To load a program with a sct tuner, but when I plug it in to the OBD-ll port it want come on like the port is dead. I know the tuner is good. Is this port fused?

 

Hi Dan, Welcome to FTE! You may get more knowledgable responses in the Super Duty thread here:
Super Duty & Heavy Duty - Ford Truck Enthusiasts Forums

I would check fuses to start. Im not sure if theses trucks are the same, but my company decided to install GPS units on our company trucks, and bought the ones that work via OBD port. On all of our 06 F250, the OBD port was dead and a fuse needed to be changed. Turns out the location of the port had A/C condensate dripping on it all the time and caused a short which blew the fuse.