My gf's car-2000 Grand Prix-does not have sound to one of the speakers in the back-anyone know why this could be-i checked the connections at the speaker and they look good

 

You (or she) have probably blown the speaker. Remove it and do the POP test with a battery. Touch a battery to the + and - input terminals of the speaker for just an instant to see if the cone jumps (pops). If it doesn't then the voice coil is toast.

 

I will try it thanks. Any other suggestions would help.