brad kay

so i've read up and followed all the advice i could find on how to diagnose my rear speakers quitting out on me (i have a 1995 GLE with the Bose system). So i took out the headunit and checked for any wiring problems that may have occured.. finding nothing out of place i replaced that and went on to testing one of the door speakers on the wiring harness for the rear deck speakers. When i did this no sound at all came through. Sooo is this most likely an amp problem? and if it is, what are the best options for fixing it. (sorry i know nothing about car audio).