Gunner

i installed a player in my friends honda civic and everything was alright. a month later we added another amp. this time, while screwing the wires back on the battery terminals the wrench hit a bolt and sparked. no bodily harm done...
we put everything back and turn on the car to find out the speedometer back lights do not work. check all the fuses in the area and none were blown. took out the instrument panel and checked the bulb and thats fine too.
honda dealer blames improper wiring, but a harness from crutchfield was used. and before the 2nd amp was added the player and dash lights worked fine.
i know its not a max but anyone have any idea as to what the problem could be. Thanks