Standard Ignition HLS1789 Headlight Switch

Headlight Switch for GMC Sierra

Standard Ignition HLS1789 is a plug-in headlight switch built for direct replacement in select GMC Sierra trucks. It uses a 12-terminal layout with a female connector, male pin terminals, and snap-fit attachment for a clean OE-style connection.

Compatible with 2020-2023 GMC Sierra 2500 HD, 2020-2023 GMC Sierra 3500 HD, 2020-2022 GMC Sierra 1500, and 2022 GMC Sierra 1500 Limited without Security Lighting, this Standard Ignition headlight switch supports factory lighting control in the correct application.

Key Features

• Standard Ignition HLS1789 headlight switch
• 12-terminal electrical design
• Female connector with male pin terminals
• Plug-in connector type for direct replacement use
• Snap-fit attachment method
• Black and chrome finish with plastic construction
• Switch function for headlight control

Detailed Description

Standard Ignition HLS1789 is a replacement headlight switch for GMC Sierra 1500, Sierra 1500 Limited, Sierra 2500 HD, and Sierra 3500 HD models listed above. The unit features one plug-in connector, a 12-terminal pin layout, and a black/chrome plastic finish that matches the original control style in many GM truck interiors. The HLS1789 part number is also referenced by HL7814, HLSB10403, S10656, and 84526545 for the same application.

Use this switch when the original headlight control has worn contacts, intermittent operation, or a damaged connector interface. Standard Ignition HLS1789 is built for direct electrical replacement where the vehicle uses the specified connector and terminal configuration.

Common Issues This Part Can Address

• Headlights do not turn on or off correctly
• Intermittent lighting control from the dash switch
• Worn or loose switch feel during operation
• Damaged connector or terminal interface at the switch
• Loss of reliable headlight control in the listed GMC Sierra models

Installation Notes and Tips

Verify the vehicle is a 2020-2023 GMC Sierra 2500 HD, 2020-2023 GMC Sierra 3500 HD, 2020-2022 GMC Sierra 1500, or 2022 GMC Sierra 1500 Limited without Security Lighting before ordering. Confirm the connector style, terminal count, and snap-fit mounting match the original switch before installation. Disconnect the battery and compare the original part number and connector layout to the new unit before transfer.

Quality Assurance

Standard Ignition is an established aftermarket brand for electrical and ignition components, and HLS1789 is built to match the specified OE-style fitment and connector configuration for the listed GMC Sierra applications.