Trying to save a 2 hour trip to dealer. Thought I would see if there may be something easy to trouble shoot. I checked balance and felt under gunnel on one non-working speaker and felt like it was connected. Bow speakers, dash, and towers all work fine. Cabin has sound out of passenger side speaker front. Haven't troubleshot much yet is there something obvious to look for before I check wiring to each speaker? Will speaker grills come off easily?