Headlight Sensor

What are Headlight Sensors and where are they Located?

Headlights are pretty straightforward at first glance. They illuminate the road in front of you, and help you see where you’re going at night. It’s pretty simple stuff. Recently though, new technologies have been added to some vehicles to make their headlights work even better. These include automatic headlights and auto-leveling headlights. These rely on electronic sensors to tell the headlights how and when to operate. 

If your car has automatic headlights then it also has an ambient light sensor. This sensor uses a photoelectric cell to determine what the lighting conditions are like outside of your vehicle. The sensor is usually mounted on the top of the dash, just behind the windshield. This gives it a good “view” of the lighting outside. 
When you’re driving in low-light conditions, like at night, at dusk or dawn, or in a parking garage, the sensor sends a signal to turn the lights on. This saves you the hassle of switching your lights on and off manually. It may be one small luxury, but, hey, it’s the little things that count, right? 

Headlight leveling sensors tell cars with self-leveling headlights when and how to adjust the lights. When the car goes over a bump, a sensor attached to the rear control arms signals the vehicle’s computer that the vehicle’s front end is higher than its lower end. The machinery for the self-adjusting headlights turns the headlight reflectors down, pointing the headlights down. That keeps them from flashing in the eyes of oncoming drivers and keeps the headlights focused on the road. 

How do I Know if my Headlight Sensors Need to be Replaced?

If your automatic headlights don’t respond to changing lighting conditions, then the ambient light sensor may be the source of the problem. The sensor can stop working or become faulty if moisture gets into it or fluid is spilled on it. The wiring to the sensor can also wear out. 

Often, sensor failure results in the headlights remaining on all the time, even in broad daylight. This can also be the result of a dirty sensor or windshield, so a little bit of cleaning might solve the problem. The sensor fuse may be the culprit. Check for these simple solutions before replacing the ambient light sensor. In some cases, a faulty sensor will keep the lights from turning on automatically. 

Of course, you will generally be able to turn the lights on and off manually with the headlight switch (if not, you have bigger problems than the light sensor). If you want the convenience of automatic lights, though, you’ll have to replace the sensor. 

Headlight level sensors, due to their placement under the frame, are exposed to dirt, road salt and moisture. Moisture can seep into the sensor and corrode the electronic parts. If this happens, then the headlights will fail to adjust when you go over bumps. Usually there will be a dash light that warns you that the lights are not adjusting. 

Can I Replace a Headlight Sensor Myself?

In general, replacing an auto headlight sensor should be pretty easy. In some cases you will be able to pop it out of the dash with a screwdriver. Then you’ll just have to disconnect the wiring harness, connect the new one, and pop it in. In other cases, you may have to remove the dash panel to access the sensor. This will make the job take a bit longer, but it should still be within the grasp of a do-it-yourselfer. 

Replacing a headlight level sensor is also pretty easy. You’ll just have to disconnect the old sensor, unbolt it from the control arm and install the new one. In some cases, you may have to remove one or more of the control arm bolts to gain access to the sensor. 

Need a Headlight Sensor Replacement?

If you are in need of a headlight sensor replacement, then you have come to the right place! Let 1A Auto be your source for aftermarket headlight sensors. We carry a large selection of headlamp sensors for many makes and models, all at great prices.

We also make shopping for a replacement headlight sensor for your vehicle easy at 1A Auto - we're here to help you select the right part for your vehicle! Call our customer service toll free at 888-844-3393 if you have any questions about our automotive headlamp sensors, warranty, compatibility or to purchase, or you can buy online.