CONNECTING TRAIN HORNS TO THE OEM HORN (18-20 FORD F150)

2018-2020 Ford F-150

You've got your horn kit assembled and you're almost ready to make some noise. If you're having trouble finding the OEM wire to tap into, this article serves to help you out. Check out the schematic below. If you're not familiar with these, don't worry, we've got you covered.

2018-2020 Ford F150 OEM Horn Wiring Schematic

Getting Started

This guide does not require you to splice or tap into any specific wire. Instead, we will pull power from the horn fuse. The horn fuse on these vehicles is only hot when the steering wheel is pressed. This makes it much easier to wire the train horns to the OEM horn. Your vehicle uses a 'MICRO2' type fuse. We recommend using an add-a-circuit to tap into this fuse. You can purchase one of these at a local Auto store, or online @ Amazon. Make sure that the connector comes with an extra fuse. If not, you will need to source a 10-amp MICRO2 Fuse.

Once you have sourced the proper add-a-circuit, we can get started with the wiring process.

  1. Start by disconnecting the negative terminal of your car battery. This will prevent any issues from occurring after we wire this up.
  2. Remove the cover from the fuse box in the engine bay. Check the back of the cover for a layout of the fuses. You are looking for the HORN fuse.
    • If you can't find your horn fuse, refer to the diagrams at this site: 2018, 2019, 2020
  3. Use a fuse puller or needle-nose pliers to remove the fuse from the fuse-box. Do not throw the fuse away, you will need it for the add-a-circuit connector.
  4. Insert your add-a-circuit into the horn fuse location. Please the original horn fuse into the add-a-circuit. This fuse goes into the terminals closest to the blades that went into the fuse box.
  5. Insert the 10-amp fuse into the terminals on the outside of the connector (as shown below)
  6. Strip one end of the supplied 18-gauge wire and crimp it into the butt connector on the end of lead coming out of the add-a-circuit.
  7. (Optional step, If you want to turn the train horn on/off. If not, skip to step 8) Route the 18-gauge wire out to a toggle switch. Connect the opposite lead of the toggle switch to the positive lead on our train horn valve.
  8. Route the 18-gauge wire from the add-a-circuit to the positive wire on our train horn solenoid valve.
  9. Make sure the opposite lead on the valve is routed to the frame of the vehicle as a ground.
  10. Check your wiring for any loose connections or frayed ends.
  11. Reconnect the battery negative terminal to the battery and press your steering wheel. The train horns should honk if there is air present in the tank.