hi i have a 2002 venture van has radio problem it works sometimes i start the van and if the radio works it will work ok till i shut off the van when you open the door the radio stops which it should do . but the next time i start the van it may not work and it might take 6 or 7 starts before the radio works again. so i tried another radio and it is locked how can i get it unlocked without paying a big price to get it unlocked . or what would be wrong with the orginal radio thanks