Aftermarket radio install ground wire short

Hi folks,
While installing an aftermarket new Kenwood stereo in my 73 Challenger, I caused a short with the black ground wire and the radio went dead. Checked the fuse on the new radio and the fuse box on the firewall. All fuses look OK, any ideas to what it could be? Also I used the cigar lighter wire for the constant power battery yellow wire.
Any help would be appreciated! Thank you, Mark
Author: Chall73