If both brake lights on your VW are not lighting, or they are staying on constantly, it is a good bet that the brake light switch has malfunctioned. The brake light switch is located on the brake pedal housing. The brake lights are illuminated when the brake pedal depresses a plunger on the brake switch. This switch is easily replaced with just a few hand tools.
Remove the screws and clips for the under-dash panel on the lower left-hand side with a Phillips head screwdriver and pliers. Remove the heater/air conditioning duct with the screwdriver. Lift the panel and duct away to expose the brake pedal mounting bracket.
Locate the electrical connector for the brake switch. Disconnect the connector from the switch and place the connector up and out of the way of the switch. The connector should release with your hand; but if it is stubborn, use the pliers to gently remove the connector.
Use a set of pliers or your hand to rotate the switch 90 degrees to the left or right. Pull the switch back and out of the bracket.
Install the new brake switch by inserting the switch into the brake pedal mounting bracket and turning the switch 90 degrees manually. The switch will firmly lock into place. Reconnect the electrical connector.
Depress the brake pedal and make sure the brake lights operate correctly. Reinstall the heater/air conditioning duct and the lower dash panel using the Phillips head screwdriver and pliers.
