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  1. Radiator Fans
  2. Derale
  3. 4000 CFM
  4. 25-5/8 Inch Diameter
  5. Electric Fans
  6. High-Output Fan
Derale 25-5/8" Dual, High-Output Electric Radiator Fan w/ Aluminum Shroud - PWM - 4,000 CFM

Derale 25-5/8" Dual, High-Output Electric Radiator Fan w/ Aluminum Shroud - PWM - 4,000 CFM

Item # D66825
Our Price: $589.19
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Radiator Fans
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Shipping Weight: 18 lbs
Derale Radiator Fans - D66825
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25-5/8" Wide x 15-1/8" tall x 4" deep. 4,000 CFM high-output dual electric puller fan cools efficiently and quietly. Variable-speed PWM controller. Dual 300-watt, 24.8-amp motors. Aluminum shroud offers top or side mount. Lowest Prices for the best radiator fans from Derale. Derale 25-5/8" Dual, High-Output Electric Radiator Fan w/ Aluminum Shroud - PWM - 4,000 CFM part number D66825 can be ordered online at or call 1-833-496-1390 for expert service.
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Derale Radiator Fans - D66825

  • 4000 CFM
  • 25-5/8 Inch Diameter
  • Electric Fans
  • High-Output Fan
  • Derale

25-5/8" Wide x 15-1/8" tall x 4" deep. 4,000 CFM high-output dual electric puller fan cools efficiently and quietly. Variable-speed PWM controller. Dual 300-watt, 24.8-amp motors. Aluminum shroud offers top or side mount.


  • High-output, dual radiator puller fan helps maintain optimal engine operating temperature
  • Efficiently moves 4,000 cubic feet per minute (CFM) of air at 0 static pressure
  • Restores horsepower and torque used by belt-driven fans
  • Draws power from the alternator, not the engine, with minimal mechanical load
  • Integrated pulse-width modulation (PWM) controller allows precise, variable fan speed control
    • Continuously monitors your engine's temperature
    • Runs fan only at precise speed needed for cooling, between 0-percent and 100-percent power
    • Can operate additional fans - up to 65 amps maximum capacity
  • Powered by dual 12V, 300-watt motors that draw 24.8 amps each
  • Soft-start technology powers up engines gradually to prevent amperage spikes
  • Moves air efficiently and quietly with skewed blades
  • Resists moisture and dirt with waterproof (IP-68) and dustproof motors
  • Increases airflow velocity with shroud
    • Rustproof aluminum shroud acts as a wind tunnel
    • Shroud can be painted, polished, or anodized
  • Designed for top or side mounting
  • Includes brackets, hardware, and installation instructions
  • Made in the USA


  • Overall dimensions: 25-5/8" wide x 15-1/8" tall x 4" deep
  • Fan diameter: 12"
  • Mounting dimensions:
    • Width: 17-3/8" - 23-3/8"
    • Length: 7-5/8" - 13-5/8"
  • Maximum CFM per fan: 2,000
  • Power draw per fan: 24.8 amps
  • 1-Year warranty

Derale A12 Dual Powerpack

Note: This assembly is intended for primary cooling and should provide enough airflow to replace your vehicle's factory fan, but you will still need to determine the CFM requirements for your engine before making your purchase. Engines that have been modified or vehicles used for towing may require additional CFM. There is no limit to the number of fans you can install, as long as they fit appropriately and are mounted on the same side of your radiator so that they do not cancel each other out.

You can install the Derale Dual Powerpack as a horsepower-boosting replacement for your belt-driven radiator cooling fan, or you can use it to upgrade or expand to your current electric fan system. The dual fan cools your engine by pulling 4,000 cubic feet per minute (CFM) through your radiator at 0 static pressure. High-output, 300-watt motors and skewed fan blades do the job efficiently and quietly. It keeps engine loads to a minimum by drawing power (49.6 amps) from the alternator - not the engine itself. An integrated pulse-width modulation (PWM) controller offers maximum cooling control and greatly reduces wear and tear. Fans operate only when needed - at the speed needed - for engine cooling. The Powerpack is neatly packaged in a slim, customizable aluminum shroud that offers multiple mounting locations and won't hog lots of space in your engine compartment.

Power Increase Compared with Belt-Driven Fans

Belt-driven radiator fans draw power from your vehicle's engine, which causes a mechanical load that robs the engine of valuable horsepower and torque. The Powerpack, on the other hand, gets its power from your vehicle's alternator, via your vehicle's 12-volt electrical system. The Powerpack's 49.6-amp draw is far less taxing to your engine than a belt-driven fan's mechanical load. So replacing your belt-driven fan with an electric fan system can increase available horsepower and torque - and even improve fuel economy.

Pulse-Width Modulation (PWM) Controller with Soft-Start Technology

Derale Dual Powerpack with Integrated PWM controller

The Powerpack's controller uses pulse-width modulation (PWM), which enables it to achieve and maintain the perfect operating speed for optimal engine cooling. The controller does this by adjusting the fan speed based on continuous, real-time engine temperature readings collected from the included sensor, which is mounted on the cool side of the radiator. Unlike conventional fan switches that have only 2 settings - on and off - the PWM controller operates at variable power levels from 0 percent to 100 percent. In some cases, for example, the engine can be kept at the desired operating temperature with fans running at between 40- and 60-percent of full operating speed. Lower operating speed means fewer cycles for the motors, which saves wear and tear and thereby potentially prolongs the life of the motors.

Soft-start technology helps protect your vehicle's electrical system by ramping fan motors up to operating speed slowly to eliminate harmful amperage spikes.

Increased Cooling Efficiency

The Dual Powerpack pulls mass quantities of air through your radiator's fins using twin fans, each powered by a 300-watt motor. The patented, skewed fan blades are designed to move air with as little noise as possible. Each fan grill is actually a stator flow director that helps produce maximum velocity by aiming the outflow.

Rustproof Aluminum Shroud

The Powerpack's rustproof aluminum shroud can be painted, polished, anodized, or left with its natural finish for a custom look. The shroud also serves as a wind tunnel so that air exits the fan quickly.

66825 Derale A12 Dual Power Pack High-Output Variable Speed RAD Fans with Pulse Width Modulation Controller - Aluminum Shroud

Video of Derale 25-5/8" Dual, High-Output Electric Radiator Fan w/ Aluminum Shroud - PWM - 4,000 CFM

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Derale Radiator Fans - Electric Fans - D66825 Review

Speaker 1: Today we're taking a look at the Derale 25 and five eighths inch, dual, high output electric radiator fan. Now this high output, dual radiator inaudible 00:00:10 fan is designed to help maintain optimal engine operating temperature. It efficiently moves 4,000 cubic feet per minute of air at zero static pressure. That's 2,000 CFM per fan. It restores horsepower and torque used by belt driven fans. And it draws power from the alternator, not the engine, with minimal mechanical load.

The unit does come with the PWM kit. That's the integrated pulse width modulation kit. So we have the controller, we have all the necessary wiring, installation brackets and hardware and the thermostat for that PWM kit. But that controller, that PWM kit allows precise, variable fan speed control. So it continuously monitors your engine's temperature, it runs the fan only at precise speed needed for cooling, between 0% and 100% power.

And it can operate additional fans up to 65 amps, max capacity.The unit's powered by dual 12 volt, 300 watt motors that draw 24.8 amps each. The wiring for those motors are located here on the backside of the unit. The unit does feature soft start technology to power up the engines gradually to prevent amperage spikes, moves air efficiently and quietly with the skewed blade design. Really nice overall design. We have the aluminum housing of the unit or shroud.

The unit also has an IP68 rating when it comes to the motors. So that's designed to resist moisture, dirt and dust. And again, the aluminum shroud is designed to really help increase airflow velocity. It's made from a rust proof aluminum, acts as a wind tunnel. The shroud can be painted, polished or anodized.

And it does come with the rubber fan shroud seal, which is located right here. And you get your insulation brackets and your hardware, wiring, everything needed for your installs included.Also comes with detailed insulation instructions to walk you through the whole process, step by step. It is designed for top or side mounting. Includes your fans, brackets, hardware, PWM kit, thermostat and instructions. Product's made in the USA. When it comes to the overall dimensions of the unit, I did take a measurement of outer edge to outer edge, and that's where we get the 25 and five eighths inch measurement from. Top to bottom is 15 and one eighths inches tall. Back to front is four inches deep. Each fan has a diameter of 12 inches and then when it comes to the mounting dimensions, the width measurements . Really you have a small room or a small area for adjustment when it comes to the mounting dimensions. So this is designed to mount anywhere from 17 and three eighths inches to 23 and three eighths inches. And then when it comes to the the length measurement of the mounting dimensions, we're looking at seven and five eighths to 13 and five eighths. That's gonna do it for today's look at the Derale dual, high output, electric radiator fan.


See what our Experts say about this Derale Radiator Fans

  • Radiator Fan for 1966 Chevy Pickup Truck
    For your 1966 Chevy Pickup I recommend taking a look at a smaller dual radiator fan like the Derale # D16812 that measures 23-3/4 inches wide, 11-1/2 inches tall, and 3 inches deep. This is going to match up much better to the mounting space you have available but its 2 high-powered electric fan assemblies will still do a great job of keeping the engine temperatures down when your truck is at a stop. Two high-amperage relay harnesses and all the necessary hardware is included. You could...
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Info for this part was:

Employee Cole B
Installed by:
Cole B
Employee Brian B
Written by:
Brian B
Employee Daron K
Updated by:
Daron K

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