How to Install an H4 LED Headlight Bulb in 10 Minutes

## Before you start You will need clean hands or nitrile gloves, and about ten minutes per side. No tools are required on most vehicles. Park on level ground, switch off the ignition and let the headlights cool for a few minutes if they were recently on. ## Step 1: Access the headlight housing Open the bonnet and locate the rear of the headlight assembly. On most hatchbacks and compact SUVs you can reach it directly. Some vehicles require removing the air intake box or washer bottle, which is usually two clips. ## Step 2: Remove the dust cap and old bulb Twist the rubber or plastic dust cap anticlockwise and set it aside. Unplug the connector from the halogen bulb, then release the wire retaining clip by pressing it inward and swinging it away. Lift the old bulb straight out. ## Step 3: Fit the LED bulb Insert the LED bulb into the housing in the same orientation as the halogen you removed. The locating tabs only allow one correct position. Secure the retaining clip. ## Step 4: Route the driver and connect Plug the LED connector into the vehicle harness. Tuck the driver box somewhere it will not touch the exhaust manifold or move against a moving part. A cable tie helps. ## Step 5: Test before reassembly Switch on the ignition and check both low and high beam. If the bulb flickers, your vehicle has canbus error detection and needs a decoder. ## Step 6: Check the beam alignment Park facing a wall about five metres away. The cutoff line should sit level and slightly below the height of the bulb itself. Adjust with the headlamp levelling screw if needed.