1998 Chevy Camaro Windows controls and radio go out occasio

My 1998 Camaro convertable has a random problem-in the middle of the day, when the temp is high, the electric windows go out, the radio stops, and the top won't go down. You can start out and all things work, then the go out and might come back on. Later that day or the next day, all seems fine. History, pulled the motor last year and put a new head gasket in and several other parts. That was over 1 year ago, and this new situation just came up.