Flex-A-Lite's New Wrangler Electric Fan



Stock Fans

Replacing the stock fan with an electric one can be done for several reasons. Gains in horsepower and torque will be achieved. Water crossings will not threaten to pull the fan into the radiator. Clearance for a different engine or radiator. Adding cooling capacity to a performance engine with the stock radiator and fan, or just replacing a worn out clutch fan. In any event choosing the right fan can be daunting.

No modern automobile manufacturer makes rigid, solid mount fans anymore for production cars. They are inefficient, pulling large amounts of power from the engine when it is not needed, and may not pull enough air at lower RPM's under heavy load to cool the engine. If they made the fan aggressive enough to cool at lower speeds, it took lots of horsepower and torque from the engine at higher speeds. Design a fan to work well at high speeds, and you may overheat at low speeds.

Manufacturers solved this puzzle with clutch fans and electric fans. Both are sensitive to the heat from the radiator, and pull more air (and power) when needed. Clutch fans however spin all the time, pulling power all the time, even if its minimized. They can be expensive to replace when they fail, not IF they fail, but when.

When your stock clutch fan starts to fail, you will not notice it right away. The clutch fan uses a viscous fluid in a veined chamber, much like a pump. As the heat from the radiator increases, a bi-metal strip coiled into a spring closes a valve, or pushes two veined plates closer together. This increases the resistance and forces the fan to turn closer to the speed of the engine pulling more air through the radiator. As the passing through the radiator cools, and the air hitting the fan is cooler, the coil will open and the resistance drops. This allows the fan to spin slower and not pull as much power from the engine. Its a great system, on demand cooling.

However seals leak fluid, vanes wear, and the bi-metal strip can fail. This does not happen all at once though. It can take months to years for you to realize something is wrong. At first you may only notice that the engine overheats just a little when sitting in traffic with the A/C on. It gets a little warmer than normal when towing, with the A/C on, up hill, against the wind. You may dismiss it. After all it came right back down didn't it? Winter comes, and it doesn't overheat, hey its cold out, you hardly need a fan to cool the engine. You forget about it, but the vanes, or spring keeps wearing, or the fluid keeps leaking out. Come next summer and your engine unexpectedly and massively overheats in Yosemite Park while driving up the pass. Stranding you in the middle of nowhere. You scramble for a new thermostat, but that does not fix it. You have the radiator professionally cleaned, that helped, but not enough. You still overheat with the A/C on while in slow traffic, or under load. You never thought about the fan, after all its still turning and moving air isn't it? Yes it is, just not enough.

Most manufacturers suggest replacing the clutch fan in as little as 5 years or 50,000mi. Its time to change the fan... Do you go with a stock replacement from your dealer $$$$$, or from (insert your favorite auto parts store)? This can cost well over $150.00 just for the part. You can replace it with an electric fan that can give you a little better gas mileage and recover some horsepower!

The Electric Fan

Flex-A-Lite manufactures a large variety of fans for many applications. Check them out at www.Flex-a-lite.com.

Many fan options exist. However; design, fit, airflow, amp draw, and availability are determining factors. Electric fans can be hard pressed to replace the stock mechanical fan in the airflow department. As such there are many small fans that are designed to help a mechanical fan or another electrical fan. These are usually straight bladed, simple shrouds, small, and noisy. Some fans can be reversed to allow them to either push the air through the front of the radiator or pull the air through from the back. Some fans are not reversible. Trying to reverse the leads to make the fan run backwards and making a pushing into a puller will not produce the desired results, and could even damage some fan motor designs.

Some fans are designed to replace the main fan. These are usually mounted on the engine side of the radiator and require removal of the stock fan. These are designed to be pullers, as they pull the air through the radiator. Some units designed to replace the main fan come in pairs. The smaller fans generally do not pull enough air over a large enough area of the radiator to cool the engine by themselves, so they use two or more of these smaller fans to cover more of the radiator. I have seen up to four fans, two pulling and two pushing, and covering all four corners to get the proper airflow over as much surface area as possible. This worked, but was very noisy, pulled allot of current, and cost quite a bit for the fans and brackets.

Many attempts at a single aftermarket replacement fan have fallen short. In general the limiting factor was balancing the size of the fan to a motor that can pull enough air and turn it reliably for a long time. All this needs to be made at a reasonable cost. Many modern engines rely on electric fans. Some newer cherokees had a combination of a small clutch fan and auxiliary electric fan. The Grand Cherokee 5.9 had a two speed full size electric fan that did a very good job of cooling the engine, and would be a marvel for the 4.0l. However the rarity and cost of this fan put it in the out of reach department.

In developing a cost effective single replacement fan for the aftermarket community has been a long time coming. Several innovations have made them more of a reality. Some of the innovations that have been made are obvious. Stronger motors, shrouds that fit a specific radiator design, and size of the fan with the advance of the motors power. Some of the less obvious changes have been in materials, blade design, and demand. If the demand is not there why spend millions to make something only a few will use?


Black Magic Xtreme

Flex-a-lite has introduced an electric fan that is a direct replacement for the Wrangler stock fan. The fan is a single speed, captured S-blade design. The S-blade design increases the surface area of the blade for a given diameter fan. It also makes for a quieter fan. The ring around the blades "captures" the air and keeps the air moving in the right direction, instead of being spun out the sides by centrifugal force. The motor is efficient, powerful, long lived, and reversible. If you have an alternative project you can turn this unit into a pusher fan. This is incorporated into a new shroud that fits over the radiator perfectly. It comes with a gasket that seals the edge. This forces all the air to pass through the radiator. Increasing efficiency over 17%. It is rated to move 3300 cubic feet of air per minute at zero static pressure.

Since I have just turned 5 years and 50k on the Jeep, its time to replace the fan. Here is how the install goes. The fan and belt can be ordered courtesy of Absolute Off-Road in Grand Junction CO. 970-245-8481 8:30 to 5:00 MST

The Install

This install is on a 2001 TJ, with a one inch body lift. The body lift lowered the engine in reference to the radiator, as you may notice in the pictures.

The fan used is Flex-A-Lite's part #485. It fits 1987 to 2006 Wranglers both 4.0 and 2.5 liter engines. It fits the TJ, LJ, YJ, and Rubicon models. It is a 12volt reversible 16 inch shrouded fan. It comes with a relay control thermostat, brackets, wires, connectors, all the bolts, and instructions. You will need to order the proper "puke" tank bracket for you engine design. Here are the instructions http://www.flex-a-lite.com/auto/485-99485.pdf from Flex-A-Lite.

Contact your local shop for information or the Flex-A-Lite web page for a list of dealers.

Flex-a-lite Consolidated
1-800-851-1510    (253) 922-2700   FAX: (253) 922-0226
P.O. Box 580  Milton, WA 98354

The installation should only take about an hour and a half it you are prepared. It will take longer if you are doing this with drinking buddies. The wiring can be difficult when you are hammered. In all it took us four hours to do the install, this included stopping for pictures, trying to get good lighting for pictures, and locating a missing tool from the bench.

Here is the stock fan and shroud, If you notice the shroud is down a bit. This is due to a one inch body lift, and we did not raise the engine. So the fan shroud had to be dropped one inch.
Here you can see two zip ties on the shroud. We had to replace the thermostat when the vehicle was purchased . So To facilitate the job, we cut the shroud into two pieces. This allowed for removal and replacement the shroud with ease.
Remove the reservoir bottle, and the two bolts that hold the shroud in place. Save the bolts, as you will use them again to install the new fan.
Here you can see where I cut the shroud. It allowed for easy removal and installation.
If you need to remove the serpentine belt to replace it. (at 50k miles, it should be done) a 1/2"
extension bar will remove the tension. Do not remove the bar until the new belt is in place. Pay attention to how the belt was threaded on the pullys. You have to get it back on the same way. Liberal Arts majors may think it looks better the "other" way, but to make the engine run right there is only one way. Take the time to look at the belt. Ours was not the same as the diagram on the radiator. We dont know why, but it cost us a half hour trying to run the belt the wrong way.
Here is the fan without the shroud in place. I removed the belt for better pictures, and it needed to be replaced.
There are two designs that hold the clutch fan in place. This one; the base shaft of the fan is a threaded nut, on the other; the base is held onto the pulley by the four bolts you see.
If you have the style with the four bolts holding the fan, you may be able to break them and remove them using a single wrench. Providing the belt is in place. If it starts to spin you may need to hold the pulley somehow.
The other style is just threaded on a big stud coming off the water pump. Take a large wrench or channel locks, and with the fan belt holding the pulley, try to unscrew the fan. It is a standard thread, and turning it to the left will unscrew it. If it is being a pain, and slipping or just not turning try this. Use the small wrench and help the belt hold the pulley with one of the four bolts. Set the wrench on the big nut, and tap it with a dead blow. You may need three hands to do this.
You can see the fan unthreading there between the pulley and the fan.

There is the old belt. When you see cracks like this on the "inside" of the belt, its time for a new one. My new belt came courtesy of Absolute Off-Road, in Grand Junction. We installed the new one. Check the diagram of the belt against the belt on the Jeep before you remove it. Ours was wrong.

The brackets line up perfectly. The instructions say to install the brackets onto the fan shroud first, we tried it the 'other' way.
We quickly decided that the people who wrote the instructions knew best. Install the brackets onto the shroud first, this is the driver side bracket. Use the hex head bolts to do this.

This is the passenger side bracket, Note the cutout for the air conditioning lines.

Install the hex bolts snug, you don't want them to move too easy, but you want to have them move if you need them to.

This is the 4.0L puke tank bracket. The 4 cyl, has a different one but it mounts in the same manner. Place it under the fan bracket. Install the shroud and bracket into the stock holes with the stock bolts. (recycling saves the environment, do your part to keep your Jeep green)
Pull the fan up snug and pinch the gasket to the to the radiator. The better the seal, the more efficient the fan .Tighten the hex bolts. (Remember you kept them loose enough to move the fan into position.)
You may have messed with the position of the fan. Check everything again, tighten all the nuts and bolts.

You are DONE! Well with the fan installation anyway.


We still have to wire the fan. Its not much but....it will only spin like a pinwheel at freeway speeds if you don't wire it up.


Here comes the part that most people hate, the wiring.

Its easy, just take your time.

Unhook the positive terminal of your battery. You do not want an 800amp surge through a wire that accidently touches ground.

Take the cover of the fuse box off. Squeeze the tabs on the top cover and lift. It will hinge at the front of the box.



Inside is the bus. I tapped the +12 line to the stud here. This protects the connection a bit, and keep the install clean looking. If you look at the battery terminal. You can see an example of clutter.
This is under the radiator. After you splice the wires for the fan, run them up and away from moving parts to the top of the engine compartment. I used a zip tie to secure the position of the wires onto the base of the radiator.

I used wire loom from Radio Shack to make the installed wires cleaner and protect them a bit. Here you can see the black and red wires sticking out of the end of the loom.

I mounted the control box where the air filter box used to be. Pre drill the holes and use the self tapping screws from Flex-A-Lite. Make sure you don't place it where it will be over exposed to heat, mud, water, etc.

The Brute Force air intake system fits here also. (Not pictured) There is enough room for the filter and the fan box. The filters heat/splash shield will protect the relay box well.

The capillary bulb is inserted into the radiator fins. I opted to install just below the inlet. This way the unit can respond quickly to high temp water from the engine.

Be very careful to not over bend, twist, crimp, flex back and forth, and or otherwise damage the fine 'wire'. It is a capillary tube and is easily damaged. It uses a fluid that expands as it heats up to activate the switch. If the tube is damaged, it will not function.

Push the bulb all the way through. Put the end cap on the end sticking out. This keeps it in place. Run the capillary tube in a manner that will protect it. Keep it away from things that will vibrate or rub.
Using a small screwdriver you can move the locking tabs and lift the whole block out of the bracket. There are four tabs.
Once the box is free, you can remove the bottom of the box to access the wires. Smaller locking tabs hold the bottom on. There are four of these tabs also.
Here is what it looks like opened up. Be careful, the wires are small and delicate.
Find a "key on" hot wire. In my case it was purple and black. (DO NOT TRUST THIS, CHECK FOR YOURSELF) Using the three way connector provided, attach the small red wire. This signal will keep the fan from activating with the engine off. The fan will only run when there is power on this line.
Attach the green with to the AC clutch line. (It was off of pin 3 of the AC clutch relay). This will turn the fan on when the compressor is running. I put electrical tape on the connections and ran the new wires out the bottom exit hole. Close up the box by assembling the bottom, then installing the mid section into the bracket, then close the top.
This is how to wire the box. The +12 is on the lower right. The green AC is just above that. The battery ground is in space three. The red key on line is in the fourth position. The Fan + and - is in the far left position. If you get these two reversed the fan will run backwards. Tie the wires down into position. The instructions are here http://www.flex-a-lite.com/auto/485-99485.pdf
Here is the finished install.

I could not find a perfect route for the capillary tube, so I did the best I could.

The tube runs into the black loom and back out near the control box.

Run the engine up to temp, you can adjust when the fan comes on with the knob on the box. Fully counterclockwise will turn the fan on sooner. Adjust it to turn on just as the water temp from the engine is at running temp. It should cycle off and on while idling. It should not be running all the time. Unless its really hot outside, and/or the A/C is on. The A/C will turn the fan on and off with the compressor.

Flex-a-lite Consolidated
1-800-851-1510    (253) 922-2700   FAX: (253) 922-0226
P.O. Box 580  Milton, WA 98354

The fans Part number is #485. You can purchase a manual on switch for the system. You can also purchase a variable speed switch from Flex-A-Lite. The part number for the variable speed control is 31165-VSC.

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