ELECTRIFYING PONY
June 23, 2025
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THE AUTO BUILDER
Featured
THE PHOENIX RISES AGAIN
You may be familiar with the fable of the Phoenix, the beautiful bird that burned and died after a spark from a cherub’s flaming sword fell into its nest. Once the flames went out, a single red egg remained and from the ashes, a new Phoenix bird hatched and so the cycle continued. This legend is similar to the lifecycle of the Honda Civic Si hatchback.
MORE POWER? BETTER SOUND? OF CORSA!
In order to thrive in the exhaust market, a company must have products with a zing factor. For Corsa, the difference begins with its materials, production techniques and efficiency of its designs. Corsa uses T-304 stainless steel, which makes each exhaust system effective, durable, attractive and easy to clean. A good grade of stainless steel makes the process of cleaning pipes about as easy as scrubbing with a Scotch-Brite pad. However, other companies also offer T-304 stainless construction, so what really sets Corsa exhausts apart? The answer is Reflective Sound Cancellation technology…
GOLDEN ARCHES
As enthusiasts, when we build our cars, we tend to stuff as much tire under those cars as possible. This is especially important for rear tires that hook the car to the ground while improving its stance. For those interested in drag-racing their cars, you will need to accommodate larger rear tires or slicks. The current hot trend is the 10.5-inch slick, which seems to work well on many applications, but depending on the make and model of your car, it may require modifications to enlarge the rear wheel openings to accommodate the larger rubber.
Spotlighter
Keeping Your Cool
Installing SPAL Electronic Cooling Fans & Controller
Author
Chris Tobin
Words & Photography
Introduction
Even though we all dream of blasting through the desert at 130-MPH like Robby Gordon, most of our 4×4 adventures take place at a much more reasonable pace. Unfortunately for our engines, crawling along a boulder-strewn dry river bed or climbing a goat trail through a mountain pass does not always allow enough airflow to keep our engines cool with a belt-driven mechanical fan. Belt-driven fans are designed to keep your engine cool when traveling down a street or highway, not while crushing boulders at 3-MPH and 1,500-RPM. So what can we do to keep our rigs from boiling over this summer? Follow along with us as we install a pair of 11-inch electronic cooling fans along with a programmable fan controller, both from SPAL USA.
SPAL Dual 11-Inch Fans
The dual 11-inch fans from SPAL can flow 2,780-cfm of air and will keep a properly equipped 800-horsepower engine cool, so they will work great with most stock and mildly modified 4×4 engines. The dual fan and shroud assembly measures approximately 23.5 inches wide, 16.25 inches high, and 4.25 inches deep. We installed the fans on our 2000 Chevy Tahoe Limited with its mildly modified 5.7-liter Vortec engine. We have driven the big SUV across the country towing a heavily loaded trailer, towed large boats for our sister magazine FAMILY and PERFORMANCE BOATING, and through the deserts of the southwest in 100-plus degree weather. The results: the SPAL fans have kept the engine cool under all operating conditions we have thrown at the rig.
Installation Overview
Including time to pause for photography, the removal of the stock fan/clutch assembly, removal, modification, and reinstallation of the fan shroud, and installation of the electronic fans and controller took about 6-7 hours. If you are mechanically and electronically inclined and plan to perform the installation yourself, give yourself a full day or maybe even a weekend to make sure you can complete the install. If, after reading about the installation on our rig, you do not feel you have the skills required to properly install the fans and controller, have the system installed by your local 4×4 shop. Just be sure to tell them your friends at 4×4 BUILDER sent you.
Modifying the Factory Fan Shroud
Rather than build a custom fan shroud to mate the new SPAL fans to the radiator at this time, we simply modified the factory fan shroud and mounted the SPAL fan assembly to the factory GM shroud. In the future, we will build a custom shroud for the truck and show you how we did it right here in 4×4 BUILDER.
SPAL Fan Controller
The SPAL FAN-PWM fan controller is easy to mount and wire and even easier to program. Measuring in at 4.75 inches high, 2.5 inches wide, and 1.25 inches deep, it is small enough to mount inside the cabin of your 4×4 but weatherproof so that it can be mounted under the hood. We chose to mount the controller along with the FRH Fan Relay Harness on the passenger side fender well between the battery and the air cleaner housing. Be sure to look for an unobstructed area to mount the units in your rig and verify that there are no wires, hoses, or other obstructions behind the panel before drilling any holes or mounting any components.
Programming the Fan Controller
When used with most modern fuel-injected engines, the SPAL fan controller can piggy-back on the factory temperature sender signal to turn the fans on and off. For older vehicles without electronic sensors, SPAL offers the FAN-PWM-TS temperature sensor that can be installed in the cooling system. When the installation is complete, the fan controller will need to be programmed; this is accomplished with the fans unplugged. To program the controller, start the vehicle with the fans unplugged and allow the engine to warm up to the desired low temperature, for example, 160 degrees. When the desired low temperature is reached, press and hold the “Low” button for 3 seconds, and the yellow LED will blink to indicate the low temperature has been programmed. Continue letting the temperature climb until the desired high temperature is reached. When the desired high temperature is reached, press and hold the “High” button for 3 seconds, and the red LED will blink to indicate the high temperature has been programmed. After programming both low and high temperature levels, shut off the engine and allow it to cool before plugging in the fans.
Normal Operation
Under normal operation, when the low temperature is reached, the yellow LED will turn on, and the fan will run at full speed for 1/2 second then begin to run at 50%. Fan speed will increase as engine temperature increases. When the high temperature is reached, the red LED will turn on, and the fan will run at 100%. Additionally, at the high temperature setting, the auxiliary fan will also turn on and run at 100%. When the engine cools to approximately 10 degrees below the high setting, the controller will switch back into low-speed mode, shutting off the auxiliary fan and slowing the primary fan. At approximately 10 degrees below the low setting, the controller will shut off the fan.
Integration with A/C Systems
The SPAL FAN-PWM will also integrate with A/C systems to run the fan(s) at full speed when the A/C system is on. The controller will work with trinary A/C systems to run the fan(s) only when the pressure requires or with standard A/C systems where the fan(s) will run whenever the A/C compressor is on. When properly installed, the green LED will turn on, and the fan(s) will run at full speed whenever the A/C is on.
Cost and Conclusion
With the entire package coming in at just under $450 without the SPAL temperature sender and around $475 with the temperature sender, it isn’t necessarily cheap. But then again, overheating and blowing your engine out on a trail in the middle of nowhere will cost a whole lot more. So if you are as serious about your rig as we are, it may be worth the investment to improve the cooling system by swapping to electronic fans. As a bonus, ditching the belt-driven fan will unleash some additional horsepower from your engine, and which one of us wouldn’t like a little more horsepower?
The SPAL FAN-PWM programmable fan controller comes with everything you need to perform the installation of one electronic fan, including well written instructions, mounting hardware and wiring connectors.
The FAN-PWM has an output to turn the second fan on and off but the FRH Fan Relay Harness is needed to actually carry the current to the second fan.
With two large electric motors and efficient 5-blade fans the SPAL 30102052 dual 11-inch cooling fan can flow almost 2,800-cfm of air at maximum capacity enough to keep a properly equipped 800-horsepower engine cool.
The twelve trap doors on the top and bottom of the fan assembly allow air to pass freely through the fan shroud at highway speeds.
Our victim for this installation is an unwitting GM 5.7-liter Vortec engine in a 2000 Tahoe Limited. The engine is slightly modified with a K&N FIPK intake system, Gibson headers and cat back system and has the factory cooling system with a belt driven fan with a thermal fan-clutch.
The space on the passenger fender well between the battery and the air cleaner assembly is where we chose to install the fan relay and controller. This location will keep our wiring runs from the battery short minimizing voltage loss through the cables.
Mounting the units on the fender of a lifted truck can be difficult and may even require a step ladder. Exercise caution when working around the battery to be sure not to short the terminals or any of your tools.
Both the FAN-PWM and the FRH are shown here installed on the fender well.
To remove the two-piece factory fan shroud the bolts must be removed along the core support and at the junction between the top and bottom halves.
To remove the two-piece factory fan shroud the bolts must be removed along the core support and at the junction between the top and bottom halves.
We found it easiest to remove the bolts at the fan shroud junction with a ratchet and multiple extensions to reach the bolts from above the top of the radiator.
We found it easiest to remove the bolts at the fan shroud junction with a ratchet and multiple extensions to reach the bolts from above the top of the radiator.
With our Tahoe the factory high-current fuse is mounted on the shroud and has to be removed prior to removing the fan shroud.
The battery cable routed over the fan shroud must be removed.
The cable is secured with push in retainers that are easiest to release with needle nose pliers from the underside as shown.
To remove the bolts for the lower half of the shroud it is easiest access them from below the truck with a ratchet and a short depth socket as shown.
With the top half of the fan shroud removed the large fan/clutch assembly is easy to see and access.
While various tools are available to hold the water pump pulley while removing the fan/clutch assembly we took the cheap route and drilled two holes in some bar stock we had floating around the shop. We then bolted it onto the water pump pulley and held the pulley in place while we removed the fan/clutch assembly.
With the fan/clutch removed the engine looks a lot simpler. In theory removing the belt driven fan can unleash up to 20-horsepower (exact figure will vary from fan to fan and engine to engine).
After removing the lower half of the fan shroud from the truck we bolted the two halves back together to size up where we will need to cut to install our SPAL fans. Notice that the fan coverage area for the dual 11-inch fans is almost the same as the opening for the factory belt driven fan.
To make room for the SPAL fans we used a rotary cutting tool to cut away part of the plastic shroud. The body of the fan shroud is made of very strong plastic that is able to support the weight of the electric fans.
After removing portions of the side walls of the fan shroud the SPAL fans fit within the open area.
We used nuts and bolts to secure the fans to the shroud with a small metal plate to prevent the nut from pulling through the plastic.
To make wiring the fans and controller easier we installed a set of Kicker battery terminals on the unused top posts of the Optima battery.
To use the looped fuse holders, cut the loop in the center.
Connect one end of the fuse holders to the positive battery terminal.
We used high quality 3M heat shrink butt connectors where possible. Notice the strain relief loop that we installed in the fuse holders.
Use a heat gun to seal the connections to protect them from the elements making sure they will last the life of the truck.
Cutting the ground cable to length and connecting it directly to the battery ensures maximum voltage at the fans at all times.
The red and black leads for the auxiliary fan are connected to the FRH high current fan relay harness with heat shrink butt connectors.
The black wires from the auxiliary fan and the FRH harness need to be connected to chassis ground or in our case directly to the negative battery terminal.
To allow the FAN-PWM to control the auxiliary fan the grey wire must be connected to the grey wire on the FRH harness. We used a standard butt connector but sealed it with 3M heat shrink tubing.
A red 3M T-tap is used on the A/C compressor lead to connect the blue wire from the controller to the truck’s A/C system to activate the fans when the A/C is on.
A red 3M T-tap is also installed on the yellow wire from the factory temperature sender (this wire may be different on your 4x4 so be sure to verify operation as outlined in the installation instructions) to connect the white wire from the SPAL controller.
Insulated male spade connectors are crimped onto the blue and white wires to fit into the T-taps installed earlier.
The male spade connectors simply push into the T-tap to make the connection. We used OEM style split-loom corrugated tubing to protect the wires and give the installation a clean OEM look.
Due to the mounting location of the electric fans the factory fuse holder had to be reoriented and installed vertically rather than its previous horizontal position.
We fed the controller’s orange wire through an existing grommet into the passenger cabin to connect to a 12-volt ignition source. In this photo the split-loom is pulled back to show the wire entering the grommet.
The orange wire is connected to a suitable ignition wire under the dash using a yellow 3M T-tap and insulated male spade connector.
Be sure to secure all wiring with the included zip ties as shown to keep them away from any moving parts of the engine including belts, pulleys and linkages.
Both fan cables need to be unplugged to perform the FAN-PWM programming.
Setting the low and high temperature values on the controller is literally as easy as pressing a button. With the fans unplugged and the engine running press and hold the “Low” button for 3-seconds when the engine reaches the desired low temperature and do the same for the “High” button when the engine reaches the desired high temperature.
After programming is complete the fans can be plugged in and the system can be tested for proper operation after the engine cools.
When the engine reaches the high temperature setting the red LED will light and the fans will run at full speed.
When the A/C is on the green LED will light and the fans will run at full speed.
ARTICLE SOURCES
SPAL Automotive USA
1731 SE Oralabor Rd.
Ankeny, IA 50021
800/345-0327
Stillwater Designs/Kicker
P.O. Box 459
Stillwater, OK 74076
405/624-8510
