well, it may very well be something else... BUT given that it APPEARS that the cable is to short.... always start with the obvious no matter how patronizing it may seem.... you said in your original post that you replaced the cable with one from the dealership.
Dealers screw up all the time, even WITHOUT customer miscommunication,... so first be absolutely sure that the cable you replaced was absolutely the right part. did you give the dealer the vin for the proper part, or did they just say "ya heres a cable for an 03 expedition"??
did you compare it to the old one before you installed it? both length and operation.
Next, be absoulutely sure that you installed it in the correct position. im not farmilliar with the vehicles cable route, but if there is a cable holder or any kind of point along the route of the cable that can adjust the reach of the cable externally, double check that.