Before you start tearing apart the steering column (if it's not too late), perform a little more diagnosis and testing.
Determine if the center (CHSML) is operating.
- If not, check the switch at the brake pedal. Also check Fuse 10.
- If the center brake lamp is working, check to see if the hazard signals are working. The hazard warning lamp switch interrupts the brake light circuit to operate the lamps as a warning (just like the turn signal switch does).
- Operate the hazard flasher switch on and off about 20 times to help wipe clean the normally closed contacts used by the brake light circuit. I've had several of these go "bad" and ended up being resurrected by operating the hazard switch rapidly on and off to reestablish adequate connections for the brake lamp circuit.
If the hazard flashers and turn signals work properly on all corners, the lamps and their connections are intact, and the problem is either the brake switch or multifunction switch, or their connections.
Replacing a switch unnecessarily would be really discouraging.