Need help with radio
 

I have a 2011 F-150 XLT that has a radio problem. I bought that truck about 3 years ago and changed out the factory speakers with some JVC speakers. Then upgraded the radio with a JVC Kenwood head unit (KW-V30BT). This has worked great until last week when the right speakers stopped working. Moving the balance to the right has no sound. Left front is good and left rear is very low. I bought a new head unit and the problem remains. I put the old factory unit back in and have the same results!
All of the wiring looks to be OK. Is there something else in the system that could be doing this?

Just because a wire looks good don't mean it is. Check inside the rubber boots where the wiring goes from the body to the door. often times it'll break inside the insulation where it can't be seen. See if any of them stretch when you tug on them.
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x2. i have sold plenty of those door harnesses

What ever happened caused 3 out of 4 speakers to be effected at the same time. I can not see wires to these speakers in doors that don't see as much use as the driver's door all going out at the same time. The right front door and right rear door speakers have NO volume, while the left rear door speaker volume is very low when the balance and fade is turned to those speakers. I wonder if there is a module that is some how tied into the sound system.

Check the wiring to the JVC.

All the wiring seems OK. As I stated in the original post, I replaced the JVC stereo with a new unit and had the same issue. I then put the original factory unit back in with the same results. Today I tried rebooting ( disconnected battery for about 1 hour) and nothing changed.
I have been looking for a wiring schematic for a 2011 XLT. I found one small photo that was blurry and it appeared the there is a module of some sorts (audio control module) after the stereo head unit and the speakers. Anyone have info on this?
My alternative is to rewire my speakers straight from the head unit to the speakers and bypass what ever is between them. This I really don't want to do!

Sometimes if you slightly bend the pin connector to the speakers better contact is made. Did this on mine on the driver side.