This procedure covers the removal and replacement of the blower motor resistor, which controls the HVAC blower motor fan speed in the 2015-2020 Ford F-150.

Warnings

Tools required

Parts

• Blower motor resistor × 1 — Motorcraft YH-1825 or equivalent

Preparation

1. Park the vehicle on level ground and ensure the ignition is off with the key removed
2. Allow the HVAC system to cool if it has been recently operated
3. Open the passenger door fully for access to the work area
4. If needed, remove floor mats from the passenger side to protect them and provide workspace

Procedure

1. 1

   Disconnect the battery negative terminal
   Locate the battery under the hood. Using a 10mm wrench or socket, loosen the negative battery terminal bolt and remove the cable from the battery post. Secure the cable away from the battery to prevent accidental reconnection.
   Torque spec

   Battery Terminal Bolts8 Nm (6 lb-ft)
2. 2

   Access the blower motor resistor area
   Position yourself in the passenger seat or kneel on the passenger floor. Look up under the dashboard on the passenger side near the center console. The blower motor resistor is mounted to the HVAC housing with the electrical connector facing downward. Use a shop light to illuminate the area.
3. 3

   Disconnect the electrical connector
   Locate the electrical connector attached to the blower motor resistor. Press the locking tab on the connector and carefully pull it straight off the resistor. You may need to wiggle it gently while applying steady pressure. Inspect the connector terminals for any corrosion or damage.
4. 4

   Remove the resistor mounting screws
   Using a 7mm socket or nut driver with a short extension, remove the two screws securing the blower motor resistor to the HVAC housing. The screws may be Phillips head or 7mm hex head depending on production date. Support the resistor with one hand while removing the second screw to prevent it from falling.
   Torque spec

   Resistor Screws2 Nm (1.5 lb-ft)
5. 5

   Remove the blower motor resistor
   Once both screws are removed, carefully pull the resistor straight out from the HVAC housing. The resistor has a seal around it that may stick slightly. Remove the old seal from the housing if it remains stuck in place.
6. 6

   Inspect the housing and connections
   Examine the opening in the HVAC housing for debris, excessive heat damage, or burn marks. Check the electrical connector for melted terminals or corrosion. If burn marks are present, this may indicate a failing blower motor drawing excessive current. Clean any debris from the housing opening with a dry cloth.
7. 7

   Install the new blower motor resistor
   Ensure the new resistor has the seal properly installed. Align the resistor with the opening in the HVAC housing and press it firmly into place until it seats completely. The resistor should sit flush against the housing surface.
8. 8

   Install the mounting screws
   Thread both mounting screws by hand first to ensure proper alignment. Using a torque wrench with 7mm socket, tighten the screws to specification in a cross pattern to ensure even seating of the resistor.
   Torque spec

   Resistor Screws2 Nm (1.5 lb-ft)
9. 9

   Reconnect the electrical connector
   Align the electrical connector with the terminals on the blower motor resistor. Push the connector straight onto the resistor until you hear or feel the locking tab click into place. Gently tug on the connector to verify it is fully seated and locked.
10. 10

    Reconnect the battery
    Return to the engine bay and reconnect the negative battery cable to the negative terminal. Tighten the terminal bolt to specification using a torque wrench.
    Torque spec

    Battery Terminal Bolts8 Nm (6 lb-ft)

Reassembly

1. Ensure all electrical connections are fully seated and locked
2. Verify no tools or parts were left under the dashboard
3. Replace floor mats if they were removed

Verification

• Turn the ignition to the ON position without starting the engine
• Test all blower motor speed settings (typically 1-7 on F-150) to ensure each speed functions properly
• Listen for smooth operation without unusual noises or grinding
• Verify airflow increases appropriately with each speed setting
• Check that the blower motor turns off completely when set to the OFF position
• Start the engine and verify blower motor operation with engine running
• Monitor for any burning smell or unusual odors from the HVAC system during initial testing

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