Auxiliary Fan

Does Your Car Need an Auxiliary Fan?

Has your vehicle been running a little bit too hot the past few days? When you’ve noticed that you tend to overheat when sitting in traffic or going uphill, then you might want to consider getting an auxiliary fan to help out your car’s radiator. This is a relatively inexpensive add-on that is quite easy to install, but you have to make sure that you get a model that’s perfect for your vehicle. Let us show you how.

Why do you overheat?

Your car’s radiator relies on the airflow coming in from your front grille to cool down your engine. When you’re driving at slower speeds, going uphill, or when you’re stuck in heavy traffic, your engine would be running at a lower RPM. As such, your belt-driven fan won’t be turning fast enough to push in enough air to cool down your radiator. An auxiliary fan will solve this problem since it will be blowing in air when you need it the most.

What to look for in an auxiliary fan?

Typical auxiliary fans tend to range somewhere between $100 - $150, and higher end models can go as high as $500 or more. We recommend that you look for a fan that doesn’t have full shrouds or unnecessary panels that could block air from reaching your radiator. Manually controlled auxiliary fans tend to be cheaper than automatic ones, but you wouldn’t want to be bothered turning a fan on and off so it’s better to spend a little bit more money and get the automatic fan instead. This is a very simple device, so you won’t have any problems when you get an OEM replacement, especially when it’s designed for your vehicle’s particular make and model. Finally, we strongly urge you to install it yourself. Installing an auxiliary fan on your own should be pretty much straightforward, so it wouldn’t make sense to waste money by hiring a mechanic to help you out.

Replacing Your Car’s Auxiliary Fan

Your vehicle should keep cool when your auxiliary fan is running properly, but unfortunately, it will deteriorate over time and should be replaced ASAP, unless you want your engine to keep on overheating. Replacing an auxiliary fan will vary from vehicle to vehicle, so it’s best to consult your car’s manual or a service guide so you’ll have an idea on how you could install an aftermarket auxiliary fan. For this guide however, we’ll be using a BMW 5-series sedan (the E36 in particular), as a way to demonstrate how easy it is to remove an auxiliary fan, and how it may look like on other similar vehicles.

Difficulty Level: Moderate

Tools that you’ll need:

• Screwdriver set
• Wrench set
• Old rag
• Can of compressed air
• Jack and jack stands
• Replacement auxiliary fan

Removing your old fan

Step 1: We always recommend that you disconnect your car’s battery before working on electrical components in your vehicle, to avoid any accidental electrocutions or short-circuiting your electronics.

Step 2: For this vehicle, you’ll need to remove the black plastic cover that’s located on top of the radiator by loosening a couple of screws. On some cars, you’ll have to remove the front bumper as well, just to access the aux fan.

Step 3: Once you’ve removed the cover, you’ll need to jack up the front of your vehicle to a comfortable height, so you could easily reach for your fan assembly from below. Make sure that you secure your car on a couple of jack stands as well.

Step 4: You’ll have to remove the fog lamp covers on this vehicle in order to access some wiring behind it that’s connected to the auxiliary fan. You might not have to do the same with other vehicles, so it’s best to consult a particular vehicle’s service manual beforehand.

Step 5: Take out the cover protecting the underside of the radiator by removing a couple of screws. Take extra care that you do not damage any of the pipes near the radiator.

Step 6: From here, you’ll have ready access to the fan assembly. Disconnect the power connector that’s attached to it before you start removing the bolts that are holding the aux fan in place. You might need to yank on the fan assembly a little bit, but just be extra careful that it doesn’t crash into nearby parts like the condenser.

Step 7: Before you start installing your new fan assembly, we advise that you take the opportunity to clean the exposed area with a rag or a can of compressed air.

Installng a new auxiliary fan

Step 1: Slide in a brand new auxiliary fan and make sure that you bolt it in tightly. Don’t forget to connect the power connector, since you won’t be able to reach this once you’ve put everything back into place.

Step 2: You should test your auxiliary fan before you place all the covers back into place. Reconnect your car’s battery and make sure that there aren’t any debris or pieces near the fan that could hit it before you start your engine. Once you’ve checked that your fan is running well, you should turn off your vehicle and place all the covers back into place.

Step 3: Once you’ve bolted on all the covers, place your car back on the ground and you are done!

Changing your auxiliary fan should be as easy as taking your old one off its mount and plugging in a replacement, but getting access to the fan itself is what differs from vehicle to vehicle. You’ll have to be patient in doing so, or have a service manual at hand, but in the end, you’ll find that it’s quite easy to finish this simple DIY repair job.