As many of us modernize our musclecars, one of the more popular mods under the hood is to upgrade the radiator to an aluminum core, with multiple rows. The aluminum radiators are typically designed to be thicker and have a bigger coolant capacity than the stock radiators.
Cooling those aluminum radiators is sometimes done with the original, factory mechanical fan, but many drivers now incorporate electric cooling fans to keep the coolant temps down during those hot August cruises, summer days, and sitting in traffic – all of which can bring your temps to uncomfortable levels.
Companies like Derale Performance can provide you with electric cooling fans with high cfm ratings to keep the air flowing, but when it comes to switching those fans on and off, there are a couple of ways you can go. One method, which is not recommended, is to route a switch under the dash, and flip it on when you drive.
The inherent problems this can create include forgetting to switch on the fan before it’s too late, or if you run it full time when the ignition is on, you’re drawing a lot of current and would need to install a relay, and extra fuses, and make sure it’s wired properly to not draw from other circuits. By the time you do all of this, hunting down the right switch, getting a relay, a fuse holder, wiring, etc., you’ve almost exceeded the cost of a Derale Thermostatic Fan Controller.
Derale has a few different models to choose from, whether you want to use a probe for in between the cooling fins on the radiator, or a sending unit that mounts to the intake, these controllers allow you to turn the fan on and off at set temperatures. You never have to switch them on manually, because all you need to do is connect them to the fan (or fans), a hot wire to the battery, a ground, and a trigger lead that can come from a switched ignition source.
The relay is built into the controller, and all necessary wires, circuit breaker, fuses and connectors are included, and the relays are able to handle nearly any electric fan you can fit under your hood, up to 35 amps. While some of the less expensive modules are designed to turn the fan on at 180 degrees, and off at 170 degrees, you can also get an adjustable module that allows you to set the temperature that you would like the fan, or fans, to kick on. This gives you more controls of when your fan operates. No more forgetting to flip that switch under the dash, you’ll be glad you went with a control module knowing that your cooling system is maintained by Derale.
Be sure to check out Derale’s web site and if you’ve been reaching down to switch on an electric cooling fan, you can get it done automatically for starting under fifty bucks. They even have one that will control dual fans, with separate relays built-in. No more forgetting to switch on the fans.