Relay w/ Built-In Fuse 40A

The FUELTECH USA Relay with Built-In Fuse 40A (MPN 3020100310) is a single-pole automotive relay designed for 12-volt electrical systems requiring reliable switching and circuit protection in a compact form factor. This relay integrates a 40-amp fuse directly into the unit, eliminating the need for external fuse holders in many aftermarket electrical applications while maintaining full load capacity for demanding circuits.

Rated at 40 amps, this relay handles high-current switching for fuel pumps, cooling fan circuits, lighting systems, and auxiliary power distribution common in performance tuning and vehicle modification projects. The integrated fuse provides circuit protection at the point of connection, reducing wiring complexity and improving system reliability. Single-pole configuration makes this a universal fit for standard 12-volt relay applications across domestic and import vehicles. Measuring 2.9 × 1.2 × 2.95 inches and weighing just 0.1 lbs, the compact design fits easily into tight engine bay locations or custom wiring harnesses without adding significant bulk.

This relay is engineered for builders and technicians working on fuel-injected engine swaps, electric fan conversions, auxiliary lighting circuits, and other 12-volt high-load applications where factory relay locations or protection schemes are insufficient. The built-in fuse approach is particularly valuable in compact installations where every cubic inch matters, such as custom harnesses, marine electrical systems, and mobile electronics platforms. Universal fitment means no proprietary mounting or harness-specific configuration required—simply integrate into your 12-volt circuit and provide adequate gauge wiring for the 40-amp load specification.