How can I test my headlights?

How to Check That Power is Getting to the Headlights: Use a Test Light

  1. Unplug the light bulb electrical connector.
  2. Turn on the headlights.
  3. Connect your test light to a good ground and touch the test light probe to the power side of the connector terminal.

How do I know if my headlight module is bad?

One of the most common symptoms of a faulty headlight switch is issues switching between headlight modes. If the headlight switch fails or wears out it can cause problems operating the headlights. A broken switch may only work on certain modes, or may cause them to come on and off intermittently and erratically.

Why is my high beam work but not low beam?

Most total headlight failures are caused by a bad component like a fuse, relay, or module. High beam headlights don’t work or low beams don’t work. The cause: A burned out bulb, or a problem with the high beam switch or relay. The fix: Replace the bulb, switch, or relay.

How can you tell if a halogen bulb is blown?

The trick is to shake the bulb lightly once the bulb has cooled off completely. If you hear something rattling around, the filament has broken, and you know the bulb has burnt out or is otherwise damaged. Low wattage bulbs may produce a very unpleasant smell if they have burnt out.

How do you check a headlight relay?

Set your meter to read in “Volts DC,” and touch the probes to the corresponding ground and power terminals in the box. You should see about 12 volts with the headlights turned on, and nothing with them off. If you see this voltage, but the headlights still aren’t working, replace the relay.

Do low beams and high beams use the same bulb?

Most modern vehicles have a single bulb with two filaments. Generally, you’ll have a standard halogen bulb for low beams, and then an HID bulb for your high beams. These are not interchangeable. Both require a different bulb (HID bulbs are significantly more expensive than halogen bulbs, as well).

Why is my left headlight not working?

If the bulb still doesn’t light up, there is a fault in the wiring harness or a corroded bulb socket and it’s time to call your mechanic for expert assistance. 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 can you tell if an LED is blown?

Connect the negative lead from the multimeter to the cathode (negative) lead on the LED. The LED should glow dimly, indicating it’s working. If the LED does not light, swap the connection to the LED leads. The LED should now light, if not the LED is faulty.