2003 Cadillac Escalade lights

The mirrors are on separate circuits and individual fuses. The power to those fuses originates at the turn signal/flasher module. I would not suspect a multifunction switch, but it is possible. I would suspect that flasher module, as it has internal logic. Are you certain that it is only the mirror indicators, and not all the turn bulbs? Looking at the schematic, in theory all should be coming on.

The service ride control is not associated with a wheel bearing. It would include automatic level control, and electronic suspension control. Do you hear your level control compressor come on after keying the vehicle up?