2008 GMC C Series Engine problems

First we were driving out of town and the radio start going on and off, the locks began going up and down until the truck lost power. The truck loses power with out any reason. We have check the battery, everything with out being able to determine why. After few minutes the truck starts up and everything goes back to normal. I am concerned that one of these days the truck is going to suddenly stop and my son could get into an accident. I bought this truck for my son to go to school and I don't feel he is safe on it for this electrical or ignition problem. *Tr