The 2006 Chevy Silverado keeps things simple when it comes to daytime running lights (DRLs). These low-powered high beams turn on automatically to help keep your truck visible during the day. If yours have stopped working but the rest of your lights are fine, there are a few known trouble spots to check.
How the DRL System Works
The DRLs on a 2006 Silverado activate when:
- The engine is running
- The transmission is in Drive
- The parking brake is fully released
- The headlights are off
- The ambient light sensor detects daylight
The DRLs use the same 9005 high-beam bulbs but run them at reduced voltage through a resistor.
Step 1: Parking Brake Switch
If the truck thinks the parking brake is engaged, it won’t activate the DRLs. Make sure the brake is fully released and that the dash warning light is off. If it still shows, the switch under the pedal may be stuck or faulty.
Step 2: Shift Into Drive
DRLs only come on when the truck is in gear. Shift into Drive with the engine running and check the front of the truck — you should see a dim glow from the high beam bulbs.
Step 3: Check the DRL Fuse
Under the hood, open the fuse box on the driver’s side. Find the fuse labeled “DRL” — usually 10A or 15A.
- Pull the fuse and inspect it for damage
- Replace it if blown with the same rating
If it continues to blow, there’s likely a short in the wiring or DRL resistor.
Step 4: Test or Swap the DRL Relay
Right near the DRL fuse is the DRL relay. These are known to fail with age. Try swapping it with another identical relay, such as for the A/C or horn. If the DRLs work after the swap, replace the relay.
Use an OEM-style part like the ACDelco D1780C.
Step 5: Inspect the DRL Resistor
This silver metal component is usually mounted to the radiator support or behind the grille. It reduces voltage to the high beams for DRL mode. If it burns out, DRLs stop working entirely.
Look for:
- Cracks or discoloration
- Corroded or melted connectors
- No continuity across terminals
Replacement is simple and costs under $30. Make sure the new one is mounted securely and out of moisture paths.
Step 6: Check the High Beam Bulbs
Even if your high beams work normally, old or cheap bulbs might not illuminate properly at reduced voltage in DRL mode.
Pull the 9005 bulbs and inspect for blackened glass or worn filaments. Replace with long-life LEDs like Fahren 9005 LED Bulbs for better visibility and longer lifespan.
Step 7: Ambient Light Sensor
Mounted on top of the dash near the windshield, this sensor tells the system when it’s bright enough to run DRLs. If it’s dirty or covered by a phone holder or dash mat, it might not trigger the DRLs.
- Clean the sensor lens
- Make sure it’s not blocked
- Replace if it’s unresponsive
Step 8: Aftermarket Headlights or Bulbs?
If you’ve installed aftermarket LEDs or HIDs, they may not be DRL compatible. These kits sometimes require more voltage than the DRL circuit supplies.
Temporarily reinstall stock halogen 9005s to test. If DRLs work again, switch to CANbus-compatible LED bulbs made for DRL use.
Wrap-Up
The DRL circuit on a 2006 Chevy Silverado is simple but depends on five or six parts working together — the fuse, relay, resistor, sensor, and bulbs. Most failures are from age or corrosion. Fixes are quick and inexpensive if you go step by step. A new relay or resistor can usually bring your DRLs back to life in less than 30 minutes.
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