I have a 2009 Hyundai Santa Fe - purchased used in 2013 - currently has 117K miles and drives well. Over the last couple of years, I've noticed that it will occasionally have a power "re-set" while I'm driving - basically, the radio "blanks out", almost like someone flipped a switch off and then immediately back on. I don't lose power to anything else (engine, transmission, etc) and no warning lights come on or flicker. Today, my son drove my car to the store, and he called me to say that he turned the key to AC, then plugged in his phone, then cranked the ignition, and all the lights and screens shut off and the car wouldn't start. So he tried a couple of times with no luck. He then tried removing the key from the ignition, opened the car door, then closed it, and tried to crank it again, and everything came on just fine, except everything from the A/C to the radio had re-set itself (all my pre-sets were gone, clock was re-set to 12:00, and my odometer/range had switched to "trip A"). No check engine lights came on, no battery light, nothing. Any idea what the issue could be???