If you have the side airbags (stock), there is a harness that runs under each one of the seats. (it's 4 or 6 pin). When you disconnect the harness and put your ignition into the "on" position, the SRS will detect a break in the line, then trip the red warning bulb.

It's a common mistake when people are running amps to the trunk. (unplug chairs, test power to amp without putting the chairs back)




If you didn't have them to begin with, You'd be fine, but I'd remove the bags before running power to the chairs.