[stich626]

they are on a timed module, that kills the lights,the dome light,radio alows you to open/close windows and all.. it surplies power to all assories untill door is opened or time runs out..
you can do the same thing(- timer) with the door switch and a relay.. use'n the switch as the relays ground, open door ground it lossed radio killed.. so you'll have 2 power sources for the radio.. you'll have to add a diode to the normal power so the relay doesn't backfeed the stock wire'n and fuse box