Replace both positive and negative battery cables on a 2015-2020 Ford F-150 with 3.5L EcoBoost engine, including all ground cable connections and cable routing.

Warnings

Tools required

Parts

• Positive battery cable assembly × 1 — Use OEM specification
• Negative battery cable assembly × 1 — Use OEM specification

Preparation

1. Ensure engine is off and key is removed from ignition
2. Allow engine bay to cool completely if vehicle was recently driven
3. Position vehicle on level ground and engage parking brake
4. Open hood and secure with prop rod
5. Take photos of cable routing before removal for reference during installation

Procedure

1. 1

   Disconnect battery negative terminal
   Using a 10mm socket, loosen the negative battery terminal bolt. Remove the terminal from the battery post and position the cable away from the battery to prevent accidental contact. Ensure the cable cannot swing back and touch the terminal.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
2. 2

   Disconnect battery positive terminal
   Using a 10mm socket, loosen the positive battery terminal bolt. Remove the terminal from the battery post. Cover the positive terminal with a shop towel or insulated material to prevent accidental grounding.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
3. 3

   Remove battery hold-down
   Using a 13mm socket, remove the battery hold-down bolt and bracket. Carefully lift the battery straight up and out of the battery tray. Set aside in a safe location.
   Torque spec

   Battery Hold-Down Bolt12 Nm (9 lb-ft)
4. 4

   Disconnect positive cable at starter and junction box
   Locate the positive cable connections at the starter motor (on passenger side of engine) and at the under-hood junction box. Using an 8mm or 10mm socket as appropriate, remove the nuts securing the positive cable terminals. Note the exact position and routing of the cable near the turbochargers to avoid heat damage during reinstallation.
5. 5

   Remove positive cable from vehicle
   Release any cable routing clips or ties securing the positive cable. Carefully route the cable out of the engine bay, noting any grommets or pass-throughs. Inspect the old cable for damage, corrosion, or wear patterns.
6. 6

   Disconnect negative cable ground connections
   Locate all negative cable ground points: primary ground to engine block (driver side of engine), chassis ground (on frame rail near battery), and any auxiliary grounds. Using a 10mm or 13mm socket, remove the ground cable bolts. Clean all grounding surfaces with a wire brush to ensure bare metal contact.
   Torque spec

   Ground Cable Bolt16 Nm (12 lb-ft)

   Ground Strap Bolts12 Nm (9 lb-ft)
7. 7

   Remove negative cable from vehicle
   Release any cable routing clips securing the negative cable. Remove the cable from the vehicle, noting routing path. Inspect mounting points and clean any corrosion from battery tray area.
8. 8

   Clean battery tray and terminals
   Use wire brush to clean battery tray, terminal posts, and all ground connection points. If corrosion is present, neutralize with baking soda and water solution, then rinse and dry thoroughly. Ensure all mounting surfaces for ground connections are clean and bare metal.
9. 9

   Install new negative cable
   Route the new negative cable following the original path documented in preparation photos. Ensure cable does not contact sharp edges or heat sources. Attach ground cable to engine block and chassis ground points. Torque all ground connection bolts to specification, ensuring clean metal-to-metal contact at each point.
   Torque spec

   Ground Cable Bolt16 Nm (12 lb-ft)

   Ground Strap Bolts12 Nm (9 lb-ft)
10. 10

    Install new positive cable
    Route the new positive cable through the engine bay, maintaining proper clearance from turbochargers, exhaust components, and moving parts. Connect cable to starter motor and junction box. Secure all cable routing clips to prevent cable movement. Do not torque terminals yet if using torque wrench - this will be done at battery connection.
11. 11

    Reinstall battery
    Place battery back into battery tray, ensuring it is seated properly. Install battery hold-down bracket and bolt. Torque hold-down bolt to specification - do not overtighten as this can damage the battery case.
    Torque spec

    Battery Hold-Down Bolt12 Nm (9 lb-ft)
12. 12

    Connect positive terminal
    Clean the positive battery post with wire brush. Apply thin coat of dielectric grease if desired. Place positive cable terminal onto battery post and hand-tighten the terminal bolt. Torque to specification using torque wrench - overtightening can strip the soft lead terminal.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)
13. 13

    Connect negative terminal
    Clean the negative battery post with wire brush. Apply thin coat of dielectric grease if desired. Place negative cable terminal onto battery post and hand-tighten the terminal bolt. Torque to specification using torque wrench. Connection will spark slightly as systems re-energize - this is normal.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Verify all cable routing matches factory configuration and cables are secured with all original clips
2. Ensure no cables contact hot exhaust components, turbos, or moving parts like drive belts
3. Double-check that all ground connections are tight and making contact with clean metal surfaces

Verification

• Turn ignition to ON position (do not start) and verify all dash lights illuminate normally
• Start engine and verify it cranks normally without hesitation
• Check that all electrical systems function properly: lights, radio, power windows, climate control
• Verify no warning lights remain illuminated on instrument cluster after startup
• Test battery voltage with multimeter: should read 12.4-12.8V key off, 13.8-14.8V engine running
• Allow vehicle to idle for 5-10 minutes to begin idle relearn process for EcoBoost engine management
• Inspect all cable connections for heat or unusual resistance after test drive

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