2013 F-150 xLT

I have a 2013 f-150 about 78k Miles on it. A month
or two after I got the truck, I was having problems
with my radio, I would turn the truck on and the
radio wouldn't start. After I drove for awhile or
turned off and started again, it would come back
on. I went to the dealership, of course had to
schedule me for Maintence but en route to my
appointment, the radio came back on and they
couldn't fix it as "there was nothing wrong". Flash
forward to where I'm out of warranty and the radio
doesn't come on at all. Turns out it was a power
issue, as in the unit wasn't getting enough power.
They referred me to a independent mechanic who
can't fix issue, sends it away to rebuilt the unit. He
gets it back, installs it in my truck. Works. But the
problem I have no is no volume control. The stereo
is obnoxiously loud and neither the volume knob or
the volume control on my steering wheel affects it.
It's not the fuse to the amplifier either. Any ideas?