In 2014 I've had to repair both 12V 'headphone jack' power receptacles above each pop out bunk due to a broken spade connector. Not sure why they failed as the harness is just stuffed up into an empty cavity and not subjected to abuse. Wouldn't surprise me if you found something similar wrong with your speaker wires.
2006 23B Hybrid with 10k round bar WDH
2011 F150 4x4 SCREW Ecoboost, Max Tow, Integrated TBC, 3.73 LS axle, Firestone Ride Rite airbags.