Only one set of speakers working. Bumps cause all to work.
This is a 99 SS with the Monsoon 6 speaker system.
I would check the connections at the individual speakers. The hatch speakers are easy to reach by just pulling out the plastic trim panels. The sail panel subs are also easy because they can be accessed by just popping the grilles. The door components are somewhat more difficult because the door trim panel must be removed but even that isn't a big job.






