GDUKOP Dual-Speed Electric Fan Wiring Harness 674-00923 for 34-inch Fans — Relay & Fused OE-Style Fit

GDUKOP 674-00923 is a complete dual-speed electric fan wiring harness and relay kit engineered to control both low and high fan speeds reliably for compatible GM trucks and SUVs.

This harness kit supplies a self-contained wiring solution to manage two-speed radiator fans when replacing or upgrading cooling components. Built to OE-style fit and tested connectors, the assembly includes relays, fuses, terminals and weatherproof wiring so you can integrate dual electric fans without cutting into vehicle circuitry. It’s aimed at 34-inch radiator fan setups and vehicles in the GM truck and full-size SUV family where dual-speed control is required.

Will this harness fit my truck or SUV?

The 674-00923 harness is made to match original routing and connector types for many Chevrolet, GMC and Cadillac models. Confirm compatibility by comparing the pictured connectors and vehicle list before purchase to ensure the pin layout and fan size match your application.

• Compatible models include Silverado 1500/2500 Classic, Avalanche 1500/2500, Suburban 1500/2500.
• Also fits GMC Sierra 1500/2500/3500 Classic, Yukon and Cadillac Escalade EXT/ESV.
• Designed for 34-inch radiator fan assemblies—verify fan diameter first.

How does the harness manage two fan speeds?

The kit uses separate relay circuits and a fused power feed to switch fans between low and high speeds for efficient temperature control. Relays handle the higher current draw while the wiring and terminals are sized to maintain reliable operation under load.

• Includes multiple relays to switch low and high speed circuits independently.
• Fused power input protects the circuit from overloads and shorts.
• Terminals and wiring gauge selected for automotive current demands.

What are the installation and durability features?

This harness is a stand-alone assembly with weatherproof connectors and heat-resistant wire insulation for longevity in engine compartments. The kit is pre-assembled to minimize splicing; installation requires following the supplied diagram and matching connections to your vehicle’s fan plugs and power source.

• Weatherproof connectors and heat-resistant insulation for harsh engine bay conditions.
• Pre-wired relays and fuses reduce the need for custom wiring work.
• OE-style terminals and tested continuity for dependable fit and function.

What should I check before buying or installing?

Inspect the harness images to confirm connector shapes and pin counts match your vehicle’s fan and wiring. If pins or connections look different, refer to the detailed images and installation notes provided to avoid mismatches during installation.

• Compare main image connector details to your fan plug and wiring harness.
• Confirm fan diameter is 34 inches as the kit expects that size range.
• Use the included relay and fuse layout to plan mounting and grounding locations.

Who is this for: Technicians, DIY mechanics, and anyone retrofitting or replacing dual electric fan controls on compatible GM trucks and full-size SUVs will benefit from this plug-and-play style harness. It’s tailored for installations that require a robust, OE-like replacement with separate low/high fan control, durable materials for long-term use in engine bays, and clear connector compatibility for Chevrolet, GMC and Cadillac models that use 34-inch radiator fan setups.