Tesla Model 3 DRL Not Working or Dim? Light Guide Strip Fix (2019-2022)

TL;DR If your Tesla Model 3 (2019–2022) has a dim or broken daytime running light (DRL), the most common culprit is a cracked light guide strip or a failing LED board inside the headlight. Instead of replacing the entire headlight assembly (which can cost thousands), you can swap in a Tesla Model 3 DRL Light Guide Strip & LED Board (2019-2022) to restore full brightness and functionality. This guide walks you through diagnosis and a step-by-step replacement.

Does this match your symptom?

Tesla Model 3 DRL dim or patchy

On 2019-2022 Model 3 the daytime light is a light guide lit by a small LED board. Patchy or dim output means one of those two parts has aged — usually both.

One side out entirely

A dead side normally means the board has failed; the guide is replaced at the same time because the two are matched for colour and brightness.

Yellow or milky light

UV exposure yellows the guide itself. If brightness is still fine but the colour is off, the guide is the failing part.

What Goes Wrong with DRLs on the Model 3 On the 2019–2022 Model 3, the daytime running lights are a sleek LED strip that wraps around the lower edge of the headlight. Many owners report that after 2–3 years, the DRL can become dim, flicker, or fail entirely. This is often due to the light guide strip (a clear acrylic piece that distributes light) becoming cloudy or cracked, or the LED board (the circuit with the LEDs) suffering a burnt-out segment. The DRL light guide and LED board are essentially the components that produce and direct the light; when they fail, you lose that signature Tesla look.

Diagnose the Problem Before ordering parts, confirm it’s the DRL and not the main headlight. Turn on the car and engage the DRL (they should be on automatically during the day). Check if one side is dimmer than the other or completely out. If the DRL is off but the turn signal and low beam work, the issue is isolated to the DRL circuit. A visual inspection may reveal a yellowed or cracked light guide, but often you’ll need to remove the headlight to see the LED board. A quick multimeter test can verify if power reaches the LED board, but for most owners, the fix is straightforward replacement.

Step-by-Step Replacement Replacing the DRL light guide and LED board requires removing the front bumper and headlight assembly. This is a moderate DIY job, but with patience, it’s doable in about 1.5–2 hours. Here’s the condensed process: 1. Disconnect the 12V battery and ensure the car is powered down. 2. Remove the front bumper by unscrewing the fender liner clips and the bolts under the bumper. 3. Unbolt the headlight assembly (three 10mm bolts) and carefully pull it out, disconnecting the electrical connectors. 4. Separate the headlight lens from the housing using a heat gun or oven (around 80°C for 10 minutes) to soften the sealant. 5. Locate the DRL light guide and LED board – they’re clipped into the lower section of the housing. Remove the old ones, noting the wiring orientation. 6. Install the new light guide and LED board (ensure they match your model year). Snap them into place and reconnect the internal connector. 7. Re-seal the headlight using fresh butyl sealant, then reassemble the headlight and bumper. 8. Reconnect the battery and test the DRLs. Pro tip: Work on a clean, soft surface to avoid scratching the lens. If you’re not comfortable with bumper removal, a professional can do this in about 2 hours.

Fix vs Replace Replacing the entire headlight assembly is the official Tesla approach and costs roughly $1,500–$2,500 per side (parts and labor). In contrast, our DRL light guide strip and LED board replacement costs a fraction of that in parts, and the install time is similar (2 hours). You keep your original housing, which means you preserve the factory fit and finish. The aftermarket part is designed to match OEM specifications, so it’s a smart, cost-effective fix.

Fitment Tips & Install Notes This part is specifically for 2019–2022 Tesla Model 3 (not the 2023+ refresh, which has a different headlight design). When ordering, double-check your vehicle’s production date (find it on the driver’s side door jamb). The light guide and LED board are sold as a set because they’re matched for brightness and color temperature. Replacing the strip while leaving the old board in place usually ends in a second failure — the two parts are matched and age together. Ensure the connectors are firmly seated, and test the DRLs before sealing the headlight completely.

FAQ Q: Can I drive with a broken DRL? A: Yes, but it’s not recommended. In many regions, DRLs are mandatory for safety, and you could fail an inspection. Plus, it affects your car’s aesthetics and resale value. Q: Will this fix the yellowing of the light guide? A: Yes, the new light guide is clear acrylic, which will restore the bright white look. The LED board also emits a consistent 6000K color temperature for a crisp white light. Q: Do I need to remove the entire bumper? A: Yes, to access the headlight bolts, you must remove the front bumper. It’s not difficult but takes about 30 minutes of careful work. Q: Is this part the same as the 2023 Model 3? A: No, the 2023 refresh has a redesigned headlight. This part is only for 2019–2022 models. Q: Both Model 3 DRLs went dark at the same time - do I need two boards? A: Boards rarely fail simultaneously, so when both sides die together the fault is usually upstream: the DRL fuse, the control module, or the wiring between them. Check the fuse first (the owner's manual lists the slot), then the module. Only replace the boards once the shared parts test fine. Q: There is moisture inside my Model 3 headlight - will a new board survive it? A: Not unless you deal with the moisture first. Water ingress is what usually kills the board, so dry the housing completely, replace the butyl seal and check the vent caps, then fit the new board. A cracked lens means the assembly itself is due.

Standards & further reading

Reference material for the standards and technology that govern vehicle lighting equipment:

Keep reading - Daytime running lights: how they work, why they fail, how to replace them - Why DRLs flicker and how to fix it - Browse every vehicle we cover

• FMVSS No. 108 - Lamps, reflective devices, and associated equipment - the US federal standard governing vehicle lighting equipment - ams OSRAM - automotive lighting - light-source and LED technology reference - HELLA - automotive lighting and electronics - vehicle lighting systems reference

Standards reference: for the Tesla Model 3, the daytime running lamp is governed by UN ECE Regulation 148 (which superseded R87) in most markets and by FMVSS 108 in the United States - these define when the lamp runs and at what output. The replacement parts restore the output those rules were written around.