Amp Location (Non JBL)

My radio and voice control volume was fine but is now very low out of the blue. I have a 2012 Tundra CrewMax Non JBL factory system with navigation, camera, CD, BT, etc. Checked all fuses, none blown. Supposedly there is an amp in the truck (there is nothing under any seat). Anyone know its location or have a suggestion to get my volume back up?

 

Welcome to the forum from Dallas...

Not sure if this is the answer, but I looked in the 2012 wiring diagrams (thank you @RainMan_PNW ).
Ultimate TUNDRA Wiring Diagrams Collection | Toyota Tundra Forum (tundras.com)

There seems to be a HU that has a built-in type amplifier.
Could that possibly be your situation?

 

If I recall correctly, the 2007-2013 only had two options for head units - “built in amp” (non-JBL) and JBL with the separate amp. The “built in” amp is simply inside the head unit, like most after market head units. If that has crapped out, you’ll have to replace the head unit.

Sometime at/after 2014 they introduced a mid-grade “premium” option that has a separate amp but isn’t the JBL system.