93 Altima having electrical problems

[JackiesuzieQ42]

My '93 altima completely lost all power while I was driving it. After 10 minutes of rest time and not turning on the radio or air conditioning the car made it home fine. I took it to the repair shop where they replaced the battery and alternator. However, they told me there is some problem electrically they just couldn't figure it out. If I turn on the air or heat and radio after a few minutes the entire engine shuts down. Also when I brake the time clock dims in everytime I brake. Anyone have any idea of what is causing this???? Please help and thanks in advance!