Why does one side of the Jetta's brake light work while the other doesn't?

[DiDonovan]

Jetta's brake light working on one side but not the other may be due to a short circuit in the wiring or a bulb malfunction. Possible short circuit scenarios: There might be a short circuit on one side of the wiring, such as: aging wires, poor contact at the connectors, etc. Solution for bulb malfunction: When one brake light is on while the other is off, this issue is usually caused by the brake bulb. Simply replacing the brake bulb can resolve the problem. Key points to note when replacing brake bulbs: When replacing brake bulbs, it's advisable to replace both simultaneously to prevent uneven filament burnout, which could lead to one light working while the other doesn't. However, you can keep a good bulb in the car as a spare for emergencies.