Ford F-150 Cooling Fan Relay Location by Model Year

Where to Find the Fan Relay on 2014–2016 Trucks

If your truck has an electric cooling fan, the relay that feeds it sits in the Battery Junction Box under the hood. Release the cover latches, lift the lid and read the diagram printed or molded on its underside. Look for a position labeled for the cooling fan or fan relay. It is often next to a high-amperage fuse that protects the same circuit. The fuse chapter of the owner's manual lists the same positions along with each fuse rating. This guide does not give a slot number because the assignment varies with engine, equipment and box revision. A guessed number is how the wrong relay gets pulled.

Model year matters. The 2014 F-150 belongs to the 2009–2014 generation. The 2015 and 2016 trucks are the redesigned aluminum-body generation, and their junction box layout is different. A location that is correct on a 2014 does not carry over slot for slot to a 2015 or 2016, and the reverse is also true. The 2015 and 2016 boxes are closely related, but you should still check the lid on your own truck.

Before you search, confirm what kind of fan you have. A fan bolted to a clutch hub at the front of the engine and driven by the belt does not use a cooling fan relay. Some belt-driven fans have an electronically controlled clutch with its own connector, and the engine computer typically controls that clutch directly. An electric fan has its motor mounted in the shroud behind the radiator, with a wiring harness plugged into it.

How the Cooling Fan Circuit Works

The powertrain control module decides when the fan should run. It goes mainly by coolant temperature, and it also considers air conditioning demand and vehicle speed. The module does not power the fan motor directly. Instead it switches a small control current through the relay coil, usually terminals 85 and 86 on a standard mini relay. When the coil energizes, the relay contacts close. That connects a fused battery feed, terminal 30, to the fan output, terminal 87. This arrangement lets a light computer circuit control a motor that draws heavy current.

Designs differ in how they handle fan speed. Some use more than one relay to give low and high speed. Others place a fan control module at the fan, which varies speed based on a pulse-width signal from the engine computer. On a fan with a control module, the junction box may only supply fused power to the module, and there may be no separate fan relay to replace. The wiring diagram for your exact truck shows which layout you have.

What Changes the Answer

Engine choice and cooling package are the biggest variables. From 2014 through 2016, the F-150 was offered with several V6 and V8 engines, and Ford did not use the same fan arrangement on every one. Towing and heavy-duty cooling equipment can also change what is installed. Production changes during a model year occasionally shift what is in the box, so two trucks of the same year can differ.

Not every relay listed in the legend is a plug-in part. On some Ford junction boxes, certain relays are built into the internal circuit board and cannot be removed individually. The lid may show a fan relay function while that spot holds no removable relay. In that case the relay may be integrated, and a failure there is a junction box repair rather than a five-minute swap.

These model years use a conventional 12-volt electrical system with a single starter battery. There is no high-voltage traction battery, so the procedures here involve only low-voltage circuits. Hybrid F-150 versions came much later. They use high-voltage components with orange cabling that require Ford's isolation procedure and trained service. Do not apply this guide to those trucks.

Safe Checks an Owner Can Make

Start by isolating the circuit. Shut the engine off, remove the key or move the key fob away, and let the engine cool. An electric fan can start on its own while the ignition is on. On some vehicles it can also run briefly after shutdown, so keep hands and tools away from the blades. Pulling or reinstalling a relay with the ignition off is generally safe. Before unplugging fan connectors or working on wiring, disconnect the negative cable from the battery terminals.

The quickest test is to swap in a known-good relay. Find a relay in the same box with an identical part number on a non-critical circuit, such as the horn, and move it into the fan position. If the fan now runs when it should, the original relay is faulty. On many trucks, running the engine with the air conditioning on will make the computer turn on the fan, which lets you feel the relay click. Always match part numbers. A relay that merely fits the socket may be wired differently inside.

A multimeter gives clearer answers. Remove the relay and leave the key off. If the circuit is fed directly from the battery, the feed terminal in the socket should read close to system voltage, around 12.6 volts on a fully charged battery. No voltage points to a blown fuse or a feed problem. With the fan running, a voltage drop test across the power and ground sides of the fan circuit reveals corroded connectors or a weak ground that slows the motor. Also check charging output with the engine running. A reading at or below battery voltage means the alternator is not keeping up, and a weak charging system can make a healthy fan seem sluggish.

Reading the Symptoms

A fan that never runs can trace to the fuse, relay, motor, connector or fan control module. It can also come from the coolant temperature signal or the engine computer itself. A fan that keeps running long after shutdown suggests relay contacts stuck closed or a module fault. It also creates a parasitic draw that can flatten the battery overnight. Pulling the relay shows whether that circuit is keeping the fan running. If the relay passes the swap test, the fault lies in the control signal or in a fan control module.

Limitations and Next Step

This guide cannot confirm the exact relay position or terminal layout for an individual truck. The reliable references are the junction box lid, the owner's manual, and a wiring diagram for your specific VIN from Ford service information or a professional repair database. A technician can use a scan tool with bidirectional controls to turn the fan on and off and to read the coolant temperature the computer is acting on. That removes much of the guesswork.

If the temperature gauge climbs while you are driving, stop and let the engine cool rather than continuing while you diagnose the fan. A shop with Ford wiring data and a scan tool is the efficient next step in three cases: the relay is built into the junction box, the truck uses a fan control module, or voltage tests do not point to a clear cause.