Headlight Switch

What is a headlight switch and where is it located?

Your car or truck headlight switch, also referred to as a headlamp switch, doesn't just turn the headlights on and off whenever you want to; it has separate components to turn on each of your parking, curb, and/or tail lights as well. Most switches also act as the instrument panel light dimmer switch and the interior courtesy light switch. In short, the headlight switch allows you to control all the lighting for your vehicle once you have inserted the key into the ignition and/or started the car or truck. This allows you to see the road, and allows other drivers to see you. It is better to see, and to be seen, than not to be seen and to hear from other angry drivers. Depending on your model, your lighting controls may be mounted on the dashboard or they may be on your turn signal switch stalk.

How do I know if my headlight switch needs to be replaced?

If your lights don’t respond to the input from the switches, then the headlight switch may be at fault.  The circuitry within the switch can become worn or damaged by electrical power surges, corrosion, exposure to moisture, or simple wear and tear from repeated use. The knobs and buttons that the driver uses to activate the lights can also become worn over time. 

If your headlights do not turn on and you know that the headlight assembly and bulb are in working order, then the problem may be in the headlamp switch. Where one headlight fails to come on, that’s generally a sign of a broken headlight; if both fail to come on, that might be a broken switch. Failing headlight switches may also leave you unable to turn on your high-beams, or, conversely, unable to turn them off. The dash lights might not turn on, or you might be unable to adjust their brightness If the switch is failing. Other symptoms of a faulty switch may include a burning electrical smell from the dash only when the lights are on, poor or faulty movement of the mechanical parts of the switch, or flickering of the lights.

Can I replace the headlight switch myself?

Most headlight switches are fairly simple to replace. Still, it would be wise to consult a repair manual for your specific vehicle. Always disconnect the battery before undertaking this repair. If the switch is on the turn signal stalk, you may need to open up the steering column. In that case, you should wait twenty minutes after disconnecting the battery to make sure that the air bag is deactivated.

On older styles in which you pull out a button to turn on the headlights, you will need to access the back of the switch. There is a small 1/4 inch button, usually facing the passenger side of the car. Pull the switch while simultaneously pressing the little button; the switch activation plunger should then come out. Next, unscrew the round nut that holds the switch to the dash. Pull the switch out from behind the dash and unplug it from the harness. Reverse these actions to install the new headlight switch replacement.

Later model vehicles with dash panel mounted headlamp switches are fairly straightforward. Usually it is necessary to take some part of the instrument panel trim apart to access the switch. If you do not know how to do this, you should consult a manual, because the plastic dash trim can be easily broken. After tackling the trim, it is usually just a matter of unbolting or unscrewing the switch, unplugging it, and re-installing. If your switch is stalk or steering column mounted, it is best to consult a service manual for the proper procedure.