This procedure covers removal and replacement of the alternator on a 2012-2018 Jeep Wrangler with the 3.6L V6 engine, including serpentine belt removal and electrical connections.

Warnings

Tools required

Parts

• Alternator × 1 — 160 amp OEM or equivalent (Mopar 05150871AC)
• Serpentine belt × 1 — Replace if worn or cracked (6-rib belt)

Preparation

1. Ensure vehicle is on level ground with parking brake engaged and transmission in Park
2. Allow engine to cool completely if recently operated
3. Photograph or sketch the serpentine belt routing before removal for reference during reinstallation
4. Gather all tools and new parts within easy reach of engine bay

Procedure

1. 1

   Disconnect battery negative terminal
   Using an 8mm socket, loosen the negative battery terminal bolt and remove the negative cable from the battery. Secure the cable away from the battery post to prevent accidental contact. Wait 2 minutes to allow capacitors to discharge.
   Torque spec

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

   Locate and document belt routing
   Verify your photo or sketch matches the belt routing diagram on the fan shroud or underhood label. The belt wraps around the alternator pulley from below. The automatic tensioner is located on the right side of the engine near the alternator.
3. 3

   Release belt tension and remove serpentine belt
   Using a 15mm wrench on the tensioner bolt head, rotate the tensioner clockwise to release tension. While holding tension released, slip the belt off the alternator pulley, then carefully release the tensioner. Remove the belt completely from all pulleys and inspect for wear or damage.
   ⚠Control the tensioner movement carefully - do not let it snap back as this can damage the tensioner mechanism
4. 4

   Disconnect alternator electrical connections
   Locate the B+ terminal connector on the back of the alternator (red protective cover). Flip up or remove the red cover, then use a 10mm socket to remove the nut securing the main power cable. Remove the cable and secure it away from the alternator. Disconnect the field circuit connector by pressing the release tab and pulling straight out.
   ℹ️The field connector has a locking tab that must be depressed - do not force the connector
5. 5

   Remove upper alternator mounting bolt
   Locate the upper alternator mounting bolt on the passenger side of the alternator bracket. Using a 15mm socket with extension, remove the upper mounting bolt completely and set aside. This is one of two bolts securing the alternator to the engine bracket.
   Torque spec

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

   Remove lower alternator pivot bolt
   Locate the lower pivot bolt that passes through the alternator mounting ear at the bottom. Using a 15mm socket, remove the pivot bolt completely. Support the alternator with your other hand as you remove this final bolt.
   ⚠Support the alternator before removing the final bolt to prevent it from falling
   Torque spec

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

   Remove alternator from engine bay
   With both mounting bolts removed, carefully maneuver the alternator upward and toward the passenger side to clear the mounting bracket. Rotate as needed to navigate past hoses and wiring. Lift the alternator out of the engine bay.
8. 8

   Prepare new alternator for installation
   Compare the new alternator to the old unit to verify correct part (pulley size, mounting ears, connector locations). Clean the mounting surfaces on the engine bracket with a wire brush to ensure proper ground contact and bolt seating. Apply a small amount of dielectric grease to the electrical connectors on the new alternator.
9. 9

   Install new alternator
   Position the new alternator into the engine bay, carefully maneuvering it into place. Align the lower mounting ear with the pivot bolt hole first, then align the upper mounting ear. Insert the lower pivot bolt finger-tight but do not fully tighten yet.
10. 10

    Install and torque mounting bolts
    Install the upper alternator mounting bolt finger-tight. Ensure the alternator is properly seated in the bracket, then torque the lower pivot bolt to 52 Nm (38 lb-ft), followed by the upper mounting bolt to 52 Nm (38 lb-ft). Torque in this sequence to ensure proper alignment.
    Torque spec

    Alternator Pivot Bolt25 Nm (18 lb-ft)

    Alternator Mounting Bolts50 Nm (37 lb-ft)
11. 11

    Reconnect alternator electrical connections
    Reconnect the field circuit connector to the alternator by pushing firmly until the locking tab clicks. Connect the main B+ power cable to the alternator output stud and install the nut, torquing to 15 Nm (11 lb-ft). Replace the red protective cover over the B+ terminal.
12. 12

    Install serpentine belt
    Following your photo or the belt routing diagram, route the new or existing belt around all pulleys except the alternator. Using the 15mm wrench, rotate the tensioner clockwise to create slack, then slip the belt onto the alternator pulley. Carefully release the tensioner to apply tension to the belt. Verify the belt is properly seated in all pulley grooves.
13. 13

    Reconnect battery
    Clean the battery terminal and cable end if necessary. Reconnect the negative battery cable to the negative terminal and torque the terminal bolt to 8 Nm (6 lb-ft). Ensure the connection is secure.
    Torque spec

    Battery Terminal Bolts8 Nm (6 lb-ft)

Reassembly

1. Double-check that all electrical connections are secure and protective covers are in place
2. Verify serpentine belt is properly routed and seated in all pulley grooves
3. Ensure no tools or parts are left in the engine bay

Verification

• Start the engine and verify the alternator is charging by observing the battery light on the dash - it should illuminate briefly then turn off
• Use a multimeter to verify charging voltage at battery terminals - should read 13.5-14.5 volts with engine running at idle
• Listen for any unusual noises from the alternator or belt area that could indicate misalignment or loose components
• Rev engine to 2000 RPM briefly and verify charging voltage remains stable and belt does not slip or squeal
• Turn on electrical accessories (headlights, blower fan, radio) and verify charging system maintains proper voltage under load

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