The aux switches on an F250 are used for customizing the vehicle. They have pre-wired switches connected to the power distribution box. Each switch is fused and can connect electrical accessories. There are six switches labeled AUX 1 to AUX 6. The switches work when the ignition is on, regardless of the engine running.

This is just a glance at what are the aux switches on an F250 Used for. The following sections cover the comprehensive discussion.

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What Functions Do the Aux Switches Serve on Ford F250?

The auxiliary switches or Upfitter switches on an F250 are used for aftermarket customization. They have pre wired switches connected to the power distribution box. Each switch is individually fused for connecting electrical accessories.

They only work when the ignition is in the on position, whether the engine is running or not. It’s recommended to keep the engine running to maintain battery charge when using the switches for an extended time or with high-current accessories.

When a switch is turned on, its indicator light illuminates, and power is provided to the device wired to that switch. AUX switch 1 is specifically for off-road lamps if your vehicle has that option.

What Accessories Can Control With Ford F250 Aux Switches?

The Ford F250 auxiliary switches can control winches, air compressors, and lighting systems. These switches are commonly used for controlling the truck’s lights. Some units also allow you to play music from the stereo system or control other auxiliary components.

The switches provide electrical battery power for various personal or commercial uses. Following are some of the most important accessories those up fitter switches (aux switches can control.

High idle control
Backup camera
Fog lights
Backup floods
SEIC (Stationary Elevated Idle Control)
On-board air compressor
Power for the pump on a 25-gallon transfer tank
Aftermarket observation camera for the fifth wheel
Aftermarket LED lighting
GPS system
Bed camera
Rear power ports for winch
Siren
Front light bar
Dash Cam
LED driving lights on the grille
Clearance lights on running boards
Trailer backup camera
Fuel pump for external tank
Air horn
CB radio
Radar detector
Backup alarm

Besides this, you can use any aftermarket accessories with the aux switches that match the amp rating of the switches and their fuses and relays. Refer to the table below for a quick overview of the amp rating of the aux switches and their fuses.

Relay	Wire Color	Wire Size	Fuse Size
AUX 1	Violet/Green	1.0 mm²	10A
AUX 2	Green/Brown	1.0 mm²	15A
AUX 3	Green/Blue	1.0 mm²	15A
AUX 4	Brown	1.0 mm²	10A
AUX 5	Blue/Orange	1.0 mm²	5A
AUX 6	Yellow/Orange	1.0 mm²	5A

Before moving further, let’s clarify what these amp ratings actually mean.

Fuse Amp Rating: The fuse amp rating is like a safety guard for your electrical system. It indicates the maximum amount of electrical current that can flow through the fuse without causing damage or posing a safety risk.

If the current exceeds the rated amperage, the fuse “blows” or breaks the circuit, preventing potential overheating or fires.

Relay Amp Rating: A relay is like a switch controlled by electricity. Its amp rating signifies the maximum current it can handle without failing. Relays are used to control high-power devices with low-power signals, like turning on headlights in a car. The relay’s amp rating ensures that it can safely handle the electrical load it’s connected to.

How to Connect Accessories With The Ford F250 Aux Switches?

To connect accessories with the Ford F250 aux switches, you will need the following tools:

Wire connectors
Electrical tape
Wire strippers
A relay (if necessary)
A multimeter (for testing purposes).

Step 1: Locate the uplifter wire

To locate the auxiliary switch wiring, there are three sets of circuits. Two sets are located under the hood and behind the battery tray, while one set is inside the vehicle near the passenger footwell.

The powered set (A) is taped behind the battery tray with a red spot tape mark. The second set (B) is also behind the battery tray, marked with white spot tape, and routes to the passenger footwell. To access the under-hood circuits, the battery and battery tray need to be removed.

Step 2: Determine the appropriate accessories

First, identify the specific components that are wired to the aux switches. The most common use is for controlling the truck’s lights, but they can also be used for other auxiliary components such as stereo systems.

Step 3: Identify the wiring for each aux switch

The switches are coded with specific labels. You will find the Power Distribution Box (PDB) switch, which corresponds to a wire color.

Similarly, the Underhood Pass Through (UHPT) switch is associated with another wire color, and the Passenger Footwell (PF) switch is linked to a wire size and fuse. To identify it accurately refer to the table below.

[The PDB is like a hub that distributes electrical power to various components in a system. Its amp rating indicates the total current capacity it can manage without overloading.]

Aux Switch	Passenger Footwell	Underhood Pass Through	Power Distribution Box
AUX 1	Violet/Green	Violet/Green	1.0 mm², 10A
AUX 2	Green/Brown	Green/Brown	1.0 mm², 15A
AUX 3	Green/Blue	Green/Blue	1.0 mm², 15A
AUX 4	Brown	Brown	1.0 mm², 10A
AUX 5	Blue/Orange	Blue/Orange	1.0 mm², 5A
AUX 6	Yellow/Orange	Yellow/Orange	1.0 mm², 5A

Step 4: Connect the accessory to the appropriate wire for the aux switch

Based on the wiring configuration, connect the accessory to the corresponding wire for the desired aux switch. For specific information on aux switches and their wiring, you should consult the owner’s manual or contact a professional mechanic. It may vary depending on the Ford F250’s model year and trim level.

Step 5: Use a relay if necessary

If the accessory requires more power than the aux switch can provide, you may need to use a relay to control the accessory. Relays are switches that activate a circuit using a small current. Consult the owner’s manual or a professional mechanic to determine if a relay is necessary and how to properly install it.

Step 6: Test the accessory

Once the connections are made, it is crucial to test the accessory to ensure it is working correctly. Turn on the aux switch associated with the accessory and verify its functionality. If the accessory is not working, double-check the wiring and connections to ensure everything is properly connected.

Remember that the specific steps for connecting accessories to the Ford F250 aux switches may vary depending on the accessory and wiring configuration. If you need specific information on connecting accessories to aux switches, consult an owner’s manual or contact a professional mechanic.

However, if you need visual guidance, you can refer to the video below.

When The Ford F250 Aux Switches are Not Recommended To Use?

The Ford F250 aux switches are generally safe to use for controlling various accessories. However, there are situations when using the aux switches is not recommended:

If the accessory needs more power than the aux switch can provide, it’s unsafe. Use a proper relay to use such accessories with Aux switches.
If the accessory isn’t compatible with the aux switch’s wiring, it can be dangerous. Check the owner’s manual or consult a mechanic for specific information.
If the accessory is not properly installed or wired, it’s unsafe. Follow the manufacturer’s instructions and use proper wiring techniques.

It’s important to remember that the situations where aux switches should not be used can vary depending on the accessory and wiring.

FAQs

How Do I Make My Ford Upfitter Switches Hot All The Time?

To make your Ford upfitter switches hot all the time, you can modify the fuse setup in the upfitter fuse box. In order to achieve the desired result, remove the plastic slider cover for the 5amp fuse and replace the 2-blade 5amp fuse with a 3-blade 5amp fuse. With this modification, all switches will receive power continuously, regardless of the key position. Therefore, you can operate the upfitter switches at any time, regardless of your vehicle’s ignition status.

Is It Possible To Add More Aux Switches To The F250?

Yes, it is possible to add more aux switches to the F250. The F250 comes with an auxiliary switchboard on the overhead console that makes aftermarket customization easier with six prewired switches connected to the power distribution box

What Does Aux Mean In A Truck?

Aux in a truck is short for “auxiliary input.” It’s a 3.5mm jack where you can connect devices with headphone connections, like phones or MP3 players. This lets you play your own music in the truck without needing Bluetooth or an FM transmitter.

Signing Off

Well, this was all about what are the aux switches on an F250 Used for.

Hopefully, you now understand the purpose of this fuse. It’s an advanced feature that allows you to add modifications to your truck. However, it’s important to remember that using accessories with higher amp ratings can have a negative impact on the battery.

Thank you!