GM GENUINE PARTS Brake Light Switch D1586H (15861245) OE-fit plunger-style factory replacement

The GM Genuine Parts D1586H (15861245) Brake Light Switch is the factory-equivalent electrical switch that activates brake lights when the brake pedal is applied.

This switch is an OE-grade replacement produced or validated by General Motors to meet original fit, form, and function for compatible GM vehicles. Designed, engineered, and tested to the same rigorous standards as factory-installed components, the D1586H integrates with vehicle electronics to ensure the brake lamp circuit responds reliably every time you press the brake pedal.

How does this switch interact with my vehicle's electronics?

The D1586H is an electrically operated plunger-style switch that completes the brake light circuit when the pedal is depressed. It is manufactured to GM specifications so signal timing and electrical resistance align with the vehicle’s original design.

• Directly connects to the brake lamp harness for consistent signal transmission.
• Designed to match OE electrical impedance and contact point spacing.
• Works with stability, cruise control, and other subsystems that monitor brake input.

Will this part fit my GM vehicle and replace the original unit?

GM Genuine Parts are intended as the recommended replacement for the factory component, and D1586H corresponds to part number 15861245 for specific vehicle applications. Confirm compatibility using your VIN or the vehicle’s parts catalog before purchasing to ensure exact fitment.

• Identical mounting points and plunger length to factory-installed switches.
• Manufactured to GM OE dimensions for proper pedal travel and engagement.
• Marked and packaged as a GM Genuine Parts item for traceability.

What are the tangible benefits of choosing a GM Genuine Parts switch?

Choosing a GM Genuine Parts switch helps preserve factory functionality and avoids surprises from aftermarket variations. The D1586H provides the durability and reliability expected from components validated by General Motors, which can reduce troubleshooting time when replacing a malfunctioning switch.

• OE-level quality minimizes fitment issues and reduces rework.
• Durable contacts and housing for long service life under normal use.
• Backed by GM’s engineering standards and part traceability.

How do I install or check the brake light switch?

Installation typically requires accessing the brake pedal area, unplugging the electrical connector, removing the retaining fastener, and fitting the new switch to the pedal bracket. After installation, verify correct pedal travel and confirm the brake lights illuminate only when the pedal is pressed.

• Disconnect battery or follow vehicle-specific safety steps before work.
• Adjust plunger position per the service manual so lights activate at the right pedal travel.
• Test operation with a helper or visual confirmation after fitting.

Who is this for: The GM Genuine Parts D1586H (15861245) Brake Light Switch is aimed at owners and technicians who want a direct-fit, OEM-quality replacement for GM vehicles. It suits anyone seeking the original equipment spec for brake light activation—especially DIY mechanics, independent repair shops, and fleet maintenance teams who require reliable, traceable GM components.