The 2002 Chevy Silverado is known for reliability — but its daytime running lights (DRLs) can sometimes stop working without warning. You hop in, start the truck, and nothing shows up in the lower headlight area during daylight. The high beams and low beams work fine, so what gives?
This guide will walk you through exactly how the DRLs work on the 2002 Silverado, what commonly causes them to fail, and how to get them working again — without guesswork.
How the DRL System Works on a 2002 Silverado
On the 2002 Silverado, the DRLs use the high beam bulbs at a reduced voltage. This happens automatically when:
- The engine is running
- The parking brake is fully released
- The transmission is in Drive
- Ambient light is bright enough (as determined by the light sensor on the dash)
So if you’re in Park or the brake is slightly engaged, the DRLs won’t activate. They also shut off automatically when the headlights turn on in low-light conditions.
Step 1: Check the Basics
- Fully release the parking brake — even a small engagement will disable the DRLs
- Shift the truck into Drive and let it idle
- Cover the ambient light sensor temporarily — the DRLs should go off if it’s working
If you do all of this and still don’t see the DRLs turn on, move on to electrical troubleshooting.
Step 2: Check the DRL Fuse
Open the under-hood fuse box on the driver’s side and locate the fuse labeled “DRL” or “DRL Module” — it should be a 10A or 15A fuse.
- Use the diagram inside the fuse cover to find the right one
- Pull it and inspect the filament
- If blown, replace with the same amperage fuse
If it blows again immediately, that’s a sign of a short circuit or a failed DRL module.
Step 3: Inspect the DRL Relay
The DRL system uses a dedicated relay located in the same under-hood fuse box. It’s often labeled “DRL Relay.”
Try swapping it with another identical relay (like the horn relay) to test it. If the DRLs begin working, the relay was your issue. A new relay costs less than $15 at most parts stores.
Step 4: Check the DRL Resistor
The DRLs on the 2002 Silverado run through a resistor to dim the high beam bulbs. This resistor is located on the radiator support behind the grille. It’s a small finned aluminum module with wires going to it.
- Look for visible damage — cracked casing, burnt smell, or melted wires
- If it’s bad, replace it with a resistor like the ACDelco GM Original Equipment Resistor
This is a common failure point in Silverados from this generation. It’s held on with a couple of bolts and is easy to replace.
Step 5: Test the Ambient Light Sensor
The sensor sits on top of the dash near the windshield — it looks like a small black dome. If it fails, the truck might think it’s dark all the time and never activate the DRLs.
Try covering the sensor with a cloth and waiting 30 seconds — the headlights should come on. Then uncover it. If nothing happens either way, the sensor may be bad.
A replacement costs about $20–$40 and plugs into the dash wiring harness. You’ll need to pop the dash bezel off to get to it.
Step 6: Check the Bulbs
The DRLs use the same bulbs as the high beams — typically 9005-style bulbs. If both are burned out or one is open internally, the DRLs won’t light. Even if the high beams work when fully powered, a failing filament might not work at DRL voltage levels.
Pull the bulbs and inspect them. Better yet, replace them with a fresh set of 9005 bulbs like the Fahren 9005 LED Headlight Bulbs. They offer better visibility and long life, and they’re plug-and-play for the Silverado.
Step 7: Wiring and Module Check
If none of the above steps work, inspect the wiring from the fuse box to the DRL resistor and light sockets. Look for:
- Chafed wires
- Disconnected or loose plugs
- Rodent damage (common on trucks stored outside)
Use a multimeter to confirm continuity through the DRL wiring. If you suspect the DRL control module is at fault and everything else checks out, that module may need to be replaced. It’s part of the vehicle lighting control and sometimes integrated into the BCM (Body Control Module).
Final Tip: DRL Delete or Disabled?
Some Silverado owners choose to disable their DRLs by removing the resistor or relay. If you recently bought the truck used, it’s possible a previous owner modified it. Double-check that all DRL components are in place and wired properly.
Wrap-Up: Don’t Ignore It
While DRLs aren’t legally required everywhere, they’re a helpful safety feature — especially on a big truck like the 2002 Silverado. Most of the time, a bad resistor or relay is the fix. With basic tools and about an hour, you can get your DRLs back in action without spending a lot.
Once they’re working again, consider upgrading to LED bulbs and cleaning all the contacts. A little preventative care now means fewer headaches later — and better visibility on the road.
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