2008 Chevrolet Chevy Express G3500, Van Passenger ExtendedFACTORY OEM SERVICE PROCEDURE

Headlamp and Panel Dimmer Switch

Fig 1: Headlamp and Panel Dimmer Switch Connector End View
GM850856Courtesy of GENERAL MOTORS CORP.
Headlamp and Panel Dimmer Switch

Pin Wire Circuit Function
1 0.35 WH 103 Headlamp Switch Headlamps On Signal
2 0.35 L-BU 13 Headlamp Switch Park Lamps Signal
3 0.35 D-GN 306 Headlamp Switch Headlamps Off Signal
4-6 - - Not Used
7 0.35 BN/WH 230 Instrument Panel Lamps Dimming Control
8 0.5 BK/WH 351 Ground
9 0.35 PU 328 Interior Lamp Defeat Switch Signal
10-11 - - Not Used
12 0.35 D-BU/WH 149 Courtesy Lamp Control
13 0.35 D-GN 44 Instrument Panel Lamps Dimmer Switch Signal
14 - - Not Used
15 0.35 OG/WH 812 IP Dimming Voltage Reference
16 - - Not Used
Connector Part Information 
  • OEM: 15416970
  • Service: See Catalog
  • Description: 16-Way F Micro-Pack 64 Series (BK)
Terminal Part Information 
  • Pins: 1-3, 7-9, 12, 13, 15
  • Terminal/Tray: 15359541/4
  • Core/Insulation Crimp: M/M
  • Release Tool/Test Probe: 15381651-2/J-35616-64B (L-BU)
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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