In message , Albert T Cone writes
It doesn't appear to be vibration related. It is after starting up, driving off and switching on the radio, and it can take a minute or two, (or longer) before I notice that the radio hasn't come on. That made my wonder whether the high starter current might temporarily make the radio see a power failure, but I have dismissed that. It doesn't happen often enough to be a real PITA, but I would like to know the reason. I'll try to note the exact circumstances every time it happens.