sounds like you may have grounded out the dash light feeder. many people mistake the dash light feeder for a ground because factory radios have a separate wire for the radio light & aftermarket radios just have it wired in with the main power, so its usually the only wire left.(but i know you have 3) go back & see what wire you hooked to the ground.try running a new ground yourself to a nut or bold on the metal body somewhere under the dash. then recheck your instrument light fuse, making sure to check all the fuse box locations, as most cars have more than one fuse box. you`ll prolly find a blown fuse, due to grounding the dash light radio feed.