[f5fstop]

kodiakz
You have not worked on many GM cars...yellow is the color GM has used for acc power for many years, and on the H3 is used for retained accessory power circuit (power that stays on after the ignition switch is turned off, and before a door is closed). Therefore, any component that is on the RAP relay is powered by a yellow wire.

However, that is minor, when compared with the information you give for the location of the amplifier. That box under the rear of the console on an H3 IS NOT an amplifier. IT IS THE AIR BAG MODULE, called the SDM (sensing and diagnostic module).
WHATEVER you do, DO NOT connect into the SDM. Messing with this device may deploy all the air bags in the vehicle. This is not only dangerous, if your head is near a bag when it is deployed, it is also very costly to replace the bags and parts of the I/P. Needless to say, this is not covered under warranty but can nominate someone for the Darwin award.

The saying for anyone who is familiar with GM vehicle wiring, is never mess with a wire that comes off a YELLOW connector. GM uses yellow connectors for the air bag system wiring.

In addition, there is NO fuse box under the left I/P, the only fuse panel is under the hood.

As for the amp, on the H3 it is located at the sub-woofer, rear left cargo area. Onstar module under center of I/P, XM receiver above glove box.

I will say you are correct when telling the person to connect to one of the orange wires under the seats for B+ power. But they do have to have power seats.