If the radio still doesn't work after replacing fuses, there is generally a diode across the incoming line for just this occasion to protect the radio components. That diode will conduct heavily on reverse polarity usually taking out the fuse before shorting the diode. If however you power up the radio and it takes out the new fuse, you will likely have to replace the diode.
Participate in life....Keep movin'....Go there....JK'n it.........Do it! Jeep #1: Red Rock 08 JK Rubicon 4dr, 6 sp manual, Stock Mud Tires, MyGIG Upgrade, Hard Top, after sale BestTop SunRider Soft Top, Congo Cage Rack, Mopar slush mats Jeep #2 Black 08 JK Rubicon 2dr, 6 sp manual, both tops, some chrome...uggg (my wife's jeep) Jeep #3 White 92 YJ (my son's jeep) A great quote from a good friend: "All hail click clack and master jk'n." Click and clack are my idols!