Ok so my brother and I are fairly new to engine work. My Mustang blew a head gasket about 3 months ago and we just got around to fixing it. We followed the book as much as possible. When it came time to start it, I turn the key and the power fades out and it clicks! the radio won't play and the trunk won't even pop! Then if I turn the key all the way back the radio and everything works fine!! Is there a certain wire I hooked up wrong? PLEASE HELP i HAVE TO GET IT BACK ON THE ROAD!