ok bought a new radio for my car i went to walmart and got a wire harness for it but it wasnt the right year for my car so i installed it anyway and order the right one at auto zone (it took 3 work days to get there) untill then i had the radio installed but the back speakers didnt work. so i thought it would work when i get the right wire harness so today i picked it up and install it and the radio doesnt work at all....is there something needed to make it work? what colors do i have to attach? also the wire harness for the 2001 grand am comes with a pink wire that the radio wire doesnt have..any help?!?