Wiring Dual Electric Fans
As many of you know, clearance between the front of your engine and radiator can be very tight. Most of the time your first thought is to find the slimmest single electric fan possible that’s powerful enough to cool your car, but wait, there’s a second option! Dual electric fans could be the solution to your cooling issues. You might think, “I don’t know how to wire up dual fans”. Here at Speedway Motors we’re happy to help you understand the process. Dual electric fans have several benefits, like being able to pull more cfm between the two fans versus having just one fan, also allowing more clearance for front engine accessories.
There are several ways that a dual fan can be wired. For example, dual thermostat switches or dual relays could be used to control each fan separately. Or a single relay could be used to control both fans. The supplied diagram is both the most reliable and easiest method I’ve found. It uses our 40-Amp Electric Relay Kit, part number 91064044, and Electric Fan Sensor, part number 91064013.
Other methods that I have used to wire up dual fans are using single relays to control both fans. I have found this to be inefficient as most dual fans pull enough load in amps at start up to blow the fuse for the relay. This should be around a 30 amp fuse in order to protect the wiring and relay.
I have also used dual thermostatic switches that control each fan individually. This method also requires more wiring and dual relays. It can also be beneficial in certain circumstances but usually is unnecessary, as most of the time you only want your fans on to cool the car down then to have them shut off. For this set up we also used two of the Speedway Universal Electric Radiator Cooling Fan, part number 910158, which comes in a 10, 12, 14, or 16 inch diameter.
The color coded diagram below will correspond with the wires on the relay kit to help simplify the wiring process. Start with taking both of the positive wires from the fans and run it to the yellow wires on each relay. You will then need switched power usually from your ignition switch, wired to the blue wires on the relays. Next, both of the black wires from the relay can be spliced together and ran to your thermostat switch. Lastly, run a fused constant power to both of the red wires on the relays. With these dual fans wired up you can keep your car cool and not have to worry about clearance issues!