40/60 Amp Dual Relay w/Wiring Harness

The DERALE 40/60 Amp Dual Relay w/Wiring Harness (MPN 16765) is engineered for automotive enthusiasts and mechanics who demand reliable auxiliary cooling system control. This dual relay assembly eliminates the guesswork from electric fan installation, delivering consistent 12-volt switching across dual high-amperage circuits. Whether you're upgrading to independent dual-fan cooling on a modified engine bay or adding a secondary cooling stage to an existing system, this kit solves the voltage-drop and relay-chattering problems that plague undersized switching solutions. The complete wiring harness eliminates fabrication errors and reduces installation time significantly.

Each of the dual relays handles up to 40 amps on the primary circuit and 60 amps on the secondary circuit, allowing true load separation and preventing voltage sag under peak demand. The relay switching mechanism uses sealed contact arms to resist corrosion in engine compartments exposed to moisture, vibration, and thermal cycling. The integrated wiring harness ships complete with correctly gauged leads, connectors, and mounting provisions—eliminating the common failure mode of mismatched wire gauges or improper crimps that cause intermittent fan dropout during heavy-load cruising or track duty. The compact 4.4 x 2.3 x 7.3-inch profile fits tight engine bays typical of performance builds, while the 0.75-pound weight adds negligible parasitic load to your electrical system.

This dual relay assembly is ideal for owners running high-output electric cooling fans on turbocharged, supercharged, or naturally aspirated engines where factory cooling falls short. Street rod builders, off-road enthusiasts, and drag racers benefit from the ability to control independent fan stages—one for cruise-speed cooling and a second for full-load peak demand. Installation pairs seamlessly with aftermarket fan controllers and thermostatic switches, allowing precise engine temperature management without relying on the OEM PCM. Mechanics appreciate the time savings of a pre-assembled harness versus field-splicing automotive-grade wire and soldering connections in cramped engine bays.