I have a 2009 CTS and recently have some electrical issues. My hazards, signal lights, and high beams do not work, nor does any feature of my dimmer switch. Basically when I turn the car on the DRL work fine but nothing happens when I turn the headlights on, high beams, signal lights, or hazards. Nothing clicks, all the fuses are good, relays seem fine, I cannot find any pinched or broken wires.
I recently replaced the headlights but these issues were not present when the lights were installed. I also installed a subwoofer in the trunk, so perhaps the vibrations dislodged a harness or something.

I have pretty much removed most of the panels, seats, etc and have not found anything. There is a thread on here with the same issue but the owner bought a different car instead. I'm not sure if I should replace the dimmer switch or if there is a rear integration module (RIM).

Any help would be appreciated.