This procedure covers the removal and replacement of the alternator on a 2011-2014 Ford F-150 equipped with the 3.5L EcoBoost V6 engine and 4WD.

Warnings

Tools required

Parts

• Alternator assembly × 1 — Use OEM specification or quality aftermarket 220-250A rating
• Serpentine belt (if worn or damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine to cool completely if recently operated
3. Disconnect negative battery terminal and secure cable away from battery post
4. Wait minimum 5 minutes for electrical system discharge
5. Take photo or diagram of serpentine belt routing for reference

Procedure

1. 1

   Remove engine cover
   Remove the plastic engine cover by pulling upward firmly on the cover to disengage the retaining grommets from the valve cover studs. Set aside.
2. 2

   Release serpentine belt tension
   Locate the belt tensioner on the driver's side of the engine. Using a 15mm wrench on the tensioner bolt, rotate the tensioner clockwise to release tension on the serpentine belt. While holding tension released, slip the belt off the alternator pulley first, then carefully release the tensioner.
   ⚠Control the tensioner release to prevent it from snapping back
3. 3

   Remove serpentine belt
   With tension released, remove the serpentine belt from the remaining pulleys and remove it from the engine bay. Inspect the belt for cracks, glazing, or excessive wear. Replace if condition is questionable.
4. 4

   Disconnect alternator electrical connections
   Locate the electrical connections on the rear of the alternator. Push down on the tab and disconnect the wiring harness connector. Remove the rubber boot covering the B+ terminal stud. Using the appropriate socket, remove the nut securing the battery cable to the B+ terminal and carefully pull the cable terminal off the stud.
   ⚠Ensure the battery cable does not contact ground or other metal components during removal
5. 5

   Remove upper alternator mounting bolt
   Locate the upper alternator mounting bolt at the top of the alternator bracket. Using an appropriate socket and extension, remove the upper mounting bolt completely. Retain the bolt for reinstallation.
   Torque spec

   Alternator Mounting Bolts50 Nm (37 lb-ft)
6. 6

   Remove lower alternator mounting bolt
   Access the lower alternator mounting bolt (pivot bolt) from underneath or through the wheel well area. Remove the bolt completely while supporting the alternator with your other hand.
   ⚠Support the alternator to prevent it from falling once the lower bolt is removed
   Torque spec

   Alternator Pivot Bolt25 Nm (18 lb-ft)
7. 7

   Remove alternator from vehicle
   With both mounting bolts removed, carefully maneuver the alternator out of the mounting bracket and engine bay. The alternator may need to be tilted or rotated to clear surrounding components. Remove through the top of the engine bay.
8. 8

   Prepare new alternator for installation
   Compare the new alternator to the old unit to verify correct replacement. Ensure all mounting ears, pulley alignment, and electrical terminal positions match. Transfer any brackets or hardware from the old alternator if necessary.
9. 9

   Install new alternator into position
   Carefully maneuver the new alternator into the engine bay and position it into the mounting bracket. Align the mounting holes with the bracket holes. You may need to pivot or tilt the alternator to achieve proper alignment.
10. 10

    Install and torque lower mounting bolt
    Insert the lower alternator pivot bolt through the mounting ear and bracket. Hand-thread the bolt until snug, then torque to specification using a torque wrench.
    Torque spec

    Alternator Pivot Bolt25 Nm (18 lb-ft)
11. 11

    Install and torque upper mounting bolt
    Insert the upper alternator mounting bolt through the bracket and alternator ear. Hand-thread until snug, then torque to specification using a torque wrench.
    Torque spec

    Alternator Mounting Bolts50 Nm (37 lb-ft)
12. 12

    Reconnect alternator electrical connections
    Position the battery cable terminal onto the B+ stud on the alternator. Install the nut and torque to specification. Reinstall the rubber protective boot over the terminal. Push the wiring harness connector onto the alternator connection point until it clicks into place.
13. 13

    Reinstall serpentine belt
    Route the serpentine belt around all pulleys according to your reference photo or the belt routing diagram on the radiator support. Leave the belt off the alternator pulley for now. Using the 15mm wrench, rotate the tensioner clockwise to release tension, then slip the belt onto the alternator pulley. Carefully release the tensioner to apply proper belt tension.
14. 14

    Verify belt installation and reinstall engine cover
    Visually verify the serpentine belt is properly seated in all pulley grooves and has no twists. Manually rotate the engine by turning the alternator pulley to confirm the belt tracks properly. Reinstall the engine cover by aligning the grommets with the valve cover studs and pressing down firmly.
15. 15

    Reconnect battery
    Clean battery terminals if necessary using a wire brush. Reconnect the negative battery cable to the battery terminal and torque the terminal bolt to specification. Do not overtighten.
    ⚠Do not overtighten battery terminal bolts as this can damage the terminal or battery post
    Torque spec

    Battery Terminal Bolts8 Nm (6 lb-ft)

Reassembly

1. Ensure all electrical connections are fully seated and secured
2. Verify serpentine belt is properly routed and tensioned
3. Confirm no tools or parts are left in the engine bay
4. Double-check all torque specifications have been met

Verification

• Start the engine and verify the alternator is operating (battery warning light should turn off within 2-3 seconds)
• With engine running, check for unusual noises from the alternator or belt area
• Using a multimeter, verify charging voltage at battery terminals is between 13.5-14.8 volts at idle
• Turn on electrical accessories (headlights, HVAC blower) and verify voltage remains stable
• Verify serpentine belt is tracking properly on all pulleys with engine running
• Check for any warning lights on the instrument cluster
• Test drive vehicle and monitor charging system performance

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