Description
When seconds count on the track, total electrical shutdown must be instantaneous and fail-safe. The Quarter-Max Large Push-Button Master Switch—widely utilized as an exterior bumper switch or kill switch—is a critical safety device engineered to sever your vehicle’s main electrical power immediately in an emergency. Featuring a high-visibility, ergonomic "Push-Off" design, it allows track safety personnel or the driver to kill the electrical system with a single, quick strike.
Built to survive the harsh environments of competitive drag racing, this switch features a fully sealed, ruggedized construction designed specifically for exterior vehicle mounting. It is impervious to harsh weather, resistant to extreme launch and track vibration, and rigorously rated to endure over 25,000 activations.
Track-Proven Reliability & NHRA Approved
This master switch is a core component of the Quarter-Max 750A Disconnect Switch Kit, which is officially approved for competitive use in the NHRA Pro Mod and NHRA Pro Stock ranks. Whether you are plumbing a professional doorslammer or upgrading a bracket racer, this kit delivers championship-grade safety and reliability to your electrical grid.
Technical Specifications
• Electrical Ratings: 10A at 24V | Up to 20A at 10–14V
• Durability: Rated for >25,000 activations
• Operating Temperature: -40°C to 100°C
• Environmental Protection: Fully sealed against weather, moisture, and severe vibration
• Connection Type: Heavy-duty screw terminals for secure, fail-safe wiring
• Dimensions: Body measures 2.6 in. long with a 1.29 in. radius | Red push-button actuator features a 1.74 in. radius
• Mounting Requirements: Requires a 19mm hole for installation (a standard 3/4 in. drill bit works in most applications); includes all necessary mounting hardware
Wiring & Installation Options
• The switch houses two independent internal circuits, providing flexible installation options to match your vehicle's wiring architecture:
• Posts A & B (Normally Closed): These terminals maintain continuity during standard operation and break the circuit when the button is depressed. Note: Use Posts A and B when pairing this switch with the Quarter-Max 750A Disconnect Kit.
• Posts C & D (Normally Open): These terminals remain open during standard operation and close continuity when the switch is activated (ideal for triggering secondary fire suppression relays, warning lights, or specialized telemetry events).
Dual-Circuit Capability: You can wire both the A/B and C/D circuits simultaneously if your complex vehicle management system requires it. Proper operation requires connecting a two-wire loop to either the A/B pair, the C/D pair, or both.
