Ipod input question

alright while i was at wal-mart picking up a wiring harness adapter and head unit mount for my stereo, i saw a rca input ipod adapter, and it was only $4, so i figured why not... so i get my stereo all hooked up (clarion dxz465mp) and put the ipod rca hookup thing in the aux ports, and then when i put my ipod in it, it only plays from the very rear speakers... and then if i leave the ipod connected and switch to a cd, the cd plays from the front speakers and the ipod plays out the back... i dont possibly think i could have messed up plugging it in, so is my problem just the fact that i got it at wal mart and it was $4?