Fordtech
i think what your looking for is called the IAT intake air temp. sensor and on the 03 ranger it is Incorporated into the MAF mass air flow sensor which should be mounted on the air filter box 6 wires going to it on one side should be gray/red then the the other end is gray with 4 wire in between

Helmut
Fordtech, you are INCORRECT. The mass air meter has 2 filaments, but neither measure temperature. I also have a 2003 Ranger with the 3.0L. The link below shows the filaments to the meter (be sure yours are clean as seen in the pic). There is indeed a separate intale air temperature sensor. The PROPER name for it is air charge temperature (ICT) sensor. Click this next link to see what is looks like (off engine). Can't believe someone would be a Ford tech and give wrong info. Thumbs down for him.