Ultra fit 32gig usb doesnt play in car

I have some what same problem playing songs in car usb stereo, but in my case the usb works ok for the very first time but if I change audio input option ( source button) to play radio or cd and then again want to play songs through usb drive it just hangs. The red led light is very bright when playing for the very first time but if I switch to radio or CD then again plays USB the led is very dim and it doesn’t play or hangs. IMO its something to do with power managment programe on ULTRA FIT USB which makes this hanging problem.