Q: How to Remove and Install the Back-up Light Switch on Buick Century and Regal?
A: For 1975-81 models with column shift automatic transmission and manual door locks, the back-up light switch is on the steering column under the instrument panel, controlled by a tang from the transmission shift tube. Install by positioning in NEUTRAL, insert the switch tang into the shift tube slot, tighten screws, and move to LOW to shear the pin. Ensure the engine starts only in PARK or NEUTRAL, adjust by setting lever in NEUTRAL, loosen screws, align switch, and tighten. For 1982-87 models, disconnect wiring, pry the switch from the column, set in NEUTRAL, align the actuator, and push down on the switch. Ensure it starts only in PARK or NEUTRAL, adjust by rotating the switch housing. Manual transmission cars usually have the back-up switch on the shifter assembly.