What would cause low beam headlights not to work?

Solution: If both headlights aren’t working, it’s unlikely that a bulb is at fault. The likely cause is a fuse, headlight relay, headlight switch, dimmer switch or a wiring fault. About the only cause that is an easy fix is a blown fuse.

How do I know if my low beam relay is bad?

Have an assistant turn on the headlights. If you hear the relay click, you know the coil is working, but you don’t know about the contacts. If you don’t hear the click, your relay is probably bad. The safest way to test a headlight relay is to replace it with a known good one.

What are the signs of a bad headlight switch?

Usually a bad or failing headlight switch will produce a few symptoms that can alert the driver of a potential issue.

Issues switching between modes. One of the most common symptoms of a faulty headlight switch is issues switching between headlight modes.
Issues with the high beams.
None of the lights work.

How do you fix headlights that won’t turn on?

My Headlights Won’t Work

Inspect the headlights to make sure the filaments are not broken.
Check the headlight fuses in the car’s fuse box.
Check the connectors, wiring harness and socket into which the headlight bulbs are plugged.
Pull out the headlight relay if the headlights still do not work.

Is there a fuse for high beams?

Blown High Beam Fuse A fuse protects the wiring from damage, in case too much current is being drawn through the high beam circuit. The fuse will blow if there’s a short circuit, but it might also blow if an accessory is drawing off it or if the bulb is the incorrect wattage.

Why are my high beams stuck on?

Dear Bruce: The most common problem is the steering column switch. Then from the lever movement the signal goes to the body control module to the high-beam relay and out to the headlights. I would check both the steering column switch and the relay. The high beams remain on until the lever is released.

Do high beams and low beams use the same bulb?

Most modern vehicles have a single bulb with two filaments. Some cars (mostly higher-end vehicles or performance vehicles) do have separate bulbs for their high and low beams. Generally, you’ll have a standard halogen bulb for low beams, and then an HID bulb for your high beams. These are not interchangeable.