2005 ford f350 superduty

I'm installing the nextel hard install car kit but need to know if the factory radio has entertainment mute and also need to find a switched accessory lead. the truck also has 5 auxilary power switches on the dash but I don't know where I can find the fuse box that go with these switches. I want to wire the car kit into one of these switches because the car is already wired for future accessories

which color is the mute lead for the radio?? thanks for your response

The radio mute wire is just an open pin on the back of the radio. Try testing with a computer safe test light. Once you hit the right pin..it will mute the radio.