Symptoms of a Bad or Failing Headlight Closure Relay
The headlight closure relay, also commonly known as the headlight motor relay, is a component that is found on vehicles equipped with motorized “pop up” or retracting headlights, that open and close. While motorized headlights are no longer commonplace with newer vehicles, they are still found on some older road going passenger cars. The headlight closure relay is the electrical relay that controls power to the headlight door motors, and allows them to open and close. When current is fed to the relay, the power circuit to the headlight is completed and the headlights will change position.
1. Headlight doors don’t open
One of the first symptoms of a failed headlight closure relay is headlight doors that don’t open. If the headlight closure relay fails it will not be able to provide the power for the headlight motors to open the headlights. The headlight bulbs may still turn on, however the headlights will be stuck in the closed position, and therefore unable to provide any light for the driver.
2. Headlight doors stuck open
Another symptom of a bad or failing headlight closure relay is headlights that remain stuck in the open position. If the relay fails when the headlights are opened it will leave the headlights stuck in the open position. The headlights may still be able to provide forward facing illumination, however they will not be able to retract. Some headlights may still be retracted manually, by turning a knob on the motor, however they will have to be manually opened and closed every time.
3. Headlight doors operate erratically and open or close on their own
Erratic headlight door operation is another symptom of a possible bad or failing headlight closure relay. A faulty relay may cause the headlight motors to malfunction and behave erratically. The headlights may open and close suddenly, on their own, or rapidly open and close, preventing the headlights from providing proper illumination. A faulty motor, or wiring can also produce similar symptoms, so having the vehicle properly diagnosed is highly recommended.
While headlight closure relays will not be found on most newer cars and trucks, they are still a component that can fail and require service, on specific older vehicles. If you suspect that your headlight closure relay may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the relay should be (replaced)[https://www.yourmechanic.com/services/headlight-closure-relay-replacement].
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Headlight Closure Relay and was authored by Eduardo Ruelas.