Hello All
So here's the deal-eo - this Cats radio intermediately blanks out panel and tunes, AC also. Literally if I turn on my blinker, roll down any window, the sunroof, plug in phone charger or media device in lighter, change hi-beams - the Radio flashes, pauses up to 10 secs comes back on will intermediately carries on this way throughout the drive. And if it's at night and my hi-beams are in use it's worse.
Got a new Duracell battery in December. Current mechanic thinks alternator which makes since because it's throwing out 16v however, the cars been quirky with wiring and settings since it's been refurbished. (hail damage, paint, some interior work. It sat in the Houston heat for years before my purchase)

 

My first thought is that you have a bad connection or bad cable on the battery. The cables are known to corrode internally and cause voltage drops. Your problem doesn't sound like a voltage surge but a voltage loss.

Try starting the car and bringing up to normal operating temperature. The turn on everything that has an electrical load. AC on high, radio, lights, high beams, seat heaters, emergency flashers, radio anything to put a heavy load on the system.

Then put your hand near the battery cables one at a time. Be careful, because you will probably find one too hot to touch. If so then that connection or cable is the problem.