2008 GMC Savana 3500 , 10ft Box Truck Former U Haul Truck

The factory radio in my 2008 GMC Savana 3500 , 10ft Box Truck Former U Haul Truck powers on and off fine as it is expected to however most of the time it powers on and no sound or music will play for a while and while driving the radio will start playing on it's own . I have not been able to figure out what the issue is .

I removed the radio when I changed out the AC / Climate Controls that are mounted above the radio and it still does the same thing .

I will most likely be replacing the radio shortly with a brand new updated head unit that has a GPS , Back Up Camera and video / digital display and need the pin out color code for the stereo plug .

Thak You in advance if you can be of assistance.