The radio and time didn’t show up on my car when I first started it. When I turned it off and back on again, everything was fine. It had been sitting a few days and it was cold out. It seems to be fine now, but I was wondering if anyone knew what happened?
Possible ignition switch.
When you turn the ignition switch to start the car , all other circuits are dead while you crank it ( gauges, radio, lights ).
When you release the key to let it run, the switch steps back to engage those other circuits.
A worn switch may be having some trouble getting contact to those other circuits.
This I know from my 80 Bronco doing just that. Wiggling the key after starting would engage the circuits and replacing the ingnition switch ( not the key/lock cylinder ) repaired everything.
How cold was it outside? A digital radio in below freezing weather will sometimes need to warm up before it operates. At 40 below in Alaska…I sometimes had to wait a few minutes before my digital display and radio worked properly.