Rear speakers are not working?

I don't know what the heck is going on with my radio, I'm only getting sound out of the front speakers. I've tried going into the settings and switching from 2 to 4 channels but that didn't work. I've also pushed the switch in the bunk that turns them off and that didn't work. I've now pulled the speaker grill off to make sure there are even speakers present and there are. They look brand new and aren't frozen like blown speakers would be. Anyways anybody have an idea of what this could be?

 

Actually turns out the sleeper switch was disconnected. Re-connected and wala works.

 

I haven't had the truck for about a month but they haven't worked from the get-go. Figured out what it was. It was the switch in the sleeper that had been disconnected. The truck must have been used for team driving at some point.

 

I did. Wasn't that.

 

it was the switch in the sleeper had been disconnected.