I own a 98 F-150 SC 4wd, I recently bought a used factory single Cd player to replace my factory tape player. I noticed when changing the two that they both have an extra place to plug in a connector in the back. The cd player has cd changer controls but not the tape player. I have read some where about cellular phone compatability whatever that means. I was wondering if any one knows what the extra plug in is for, or any information would be of help.

 

The extra plug in might be for the premium sound. basically an amp plug in. Are you sure of the cd player having controls for the external cd changer? The only radio that came from the factory for the F150's and F250 light duties that had controls for the cd changer did not have a single cd in the head unit, they only had a cassette. The 97 and 98 models had the same radios, and the 99's have a new style.(at least this is true of trucks coming out of the Kansas City plant) If the head unit you have has a cd in it as well as the changer controls, either it was something the dealer put in or is from another Ford model.