Chevrolet headlight switch wiring how to connect step by step guide diagram included

This guide provides a step-by-step Chevrolet headlight switch wiring connection procedure. Refer to the terminal view diagram below.

Terminal Functions & Wire Colors (Typical - Confirm Model Specific Diagram)

• Terminal A (Battery Feed/Input):
  • Connect constant +12V power source (usually fused, directly from battery or distribution block).
  • Often uses a Red wire or Orange wire.
• Terminal B (Parking Lights Output):
  • Output to parking lights and instrument panel illumination.
  • Commonly Brown wire or Grey wire.
• Terminal C (Dimmer (Instrument Lights) Input):
  • Connection for the dash dimmer control potentiometer.
  • Typically Gray wire or Tan wire.
• Terminal D (Headlight Switch Ground):
  • Connect to a clean chassis or dash metal ground point.
  • Usually a Black wire.
• Terminal E (Headlights Output - Low Beam):
  • Output feeding low beam headlights (often via relay).
  • Frequently Tan wire or Yellow wire.
• Terminal F (Headlights Output - High Beam):
  • Output feeding high beam headlights (often via relay).
  • Often Light Blue wire or Green wire.
• Terminal G (Daytime Running Lamps (DRL) - If Equipped):
  • Output for DRL module/power.
  • Wire color varies widely; check diagram (Dark Green common).

Terminal Diagram Layout

Visualize the switch back terminal locations:

A B C

D E F G

(Where A, B, C are the top row; D, E, F, G are the bottom row)

Connection Steps

1. Disconnect Battery: Always disconnect the negative battery terminal before wiring.
2. Access Switch Socket: Remove the necessary trim/dash panels to access the headlight switch wiring socket/plug.
3. Identify Wires: Match existing vehicle harness wires to the terminal functions listed above using a multimeter or wiring diagram.
4. Connect Ground: Securely attach the switch's ground wire (Terminal D - Black) to a solid bare metal chassis point.
5. Connect Battery Feed: Connect the fused constant +12V power source wire to Terminal A (Red/Orange).
6. Connect Outputs:
   • Parking Lights: Harness wire to Terminal B (Brown/Grey).
   • Dimmer Control: Connect dimmer potentiometer wires per diagram to Terminal C (Gray/Tan).
7. Connect Headlight Feeds:
   • Low Beam Output: Harness wire to Terminal E (Tan/Yellow).
   • High Beam Output: Harness wire to Terminal F (Light Blue/Green).
8. Connect DRL (If Equipped): Connect the DRL output wire to Terminal G (e.g., Dark Green) per the vehicle schematic.
9. Secure Socket: Reinsert the wiring plug/socket firmly into the switch back.
10. Reconnect Battery & Test: Reconnect the battery negative terminal and thoroughly test all lighting functions: parking lights, headlights (low/high beams), instrument dimming, and DRL (if equipped).

Important Notes:

• Model Variations: ALWAYS obtain the specific wiring diagram for your Chevrolet year/model. Terminal locations, functions, and wire colors vary.
• Relay Integration: The switch outputs (Terminals E & F) usually control relays supplying high current to the headlights directly. Check relay wiring if headlights malfunction.
• Circuit Protection: Ensure all circuits have adequate fuse protection per the factory diagram.
• Multimeter Use: Essential for verifying wire functions and power/ground.