How to Replace Third Brake Light 03-07 Cadillac CTS
Difficulty: Beginner · About 45 min · Cadillac Cts
Replace the center high mount stop lamp on a 2003–2007 Cadillac CTS by removing the trunk liner and rear trim panel.
Tools you will need
- Flat Blade Screwdriver
- T15 Torx Driver
- 10mm Socket
- Ratchet
- Trim Tool Set
Parts and supplies
- Center brake light assembly
Steps
Remove the trunk liner
Open the trunk and loosen the center retainers with a flat screwdriver. Release the outer clips with a trim tool and lower the liner to expose the rear trim panel fasteners.
Remove the exterior trim panel
Unplug the trim panel connector and remove its mounting nuts. Ease the panel away from the trunk without bending it, then disconnect the brake lamp wiring.
Replace the center brake lamp
Remove the lamp's Torx fasteners and release its harness retainer. Lift the old lamp from the panel, install the replacement in the same orientation, secure its screws, and reconnect the wiring.
Reinstall the trim and test the lamp
Align the exterior trim studs with the trunk slots, reinstall its nuts, and reconnect the harness. Refit the trunk liner and retainers, then press the brake pedal and confirm the center lamp illuminates.
Check your vehicle’s repair manual for exact specifications and fit.