How to Change an Alternator in a 2002 Ford Explorer 4X4by Jody L. Campbell; Updated November 07, 2017
Items you will need
Serpentine belt tool
Ratchet, extension and socket set
The 2002 third-generation Ford Explorer most commonly featured the Cologne V6 4.0-liter engine. Although a 4.6-liter V8 was also available in 2002, the V6 engine accounted for most of the sales of the mid-size Ford SUV. Whether it's 4X4 or not does not affect the removal and replacement of the alternator; however, the V8 has a slightly different procedure and serpentine belt routing diagram.
Locate the belt routing diagram in the engine compartment. This is for reference only in case the belt becomes disengaged from other pulleys during the procedure. If you cannot locate the belt routing diagram, either refer to the owner's manual or illustrate your own.
Loosen the black-wired negative battery terminal clamp with a wrench. Wiggle the terminal clamp back and forth on the battery post with a pair of channel locks to loosen, then remove it from the battery post. Isolate the clamp so it does not come into contact with the battery post during the alternator replacement. Repeat this procedure for the red-wired positive battery terminal clamp.
Locate the alternator on the passenger side of the engine. Below the alternator is where the belt tensioner pulley is located. Place a 1/2-inch drive adapter into the serpentine belt tool, insert the tool into the square drive of the belt tensioner pulley, and then turn it counterclockwise to release tension on the serpentine belt. Remove the belt from the alternator pulley only. You do not need to remove the entire belt, but this is a good opportunity to inspect the belt for dry cracks and replacement, if necessary.
Remove the B+ terminal cover from the alternator and then remove the B+ terminal nut using a ratchet and socket. Remove the B+ terminal and the two electrical connections from the alternator.
Locate the three alternator bolts. They are accessible from the passenger side front fender. There are two on the bottom and one on the top of the alternator. Remove the alternator bolts using the ratchet, an extension and a socket.
Remove the alternator.
Install the new alternator by reversing the procedure. Be sure the ribs of the serpentine belt are properly aligned in the grooves of all the pulleys when placing it back onto the alternator pulley. Be sure to attach the positive battery terminal clamp to the battery first and then the negative battery terminal clamp to avoid sparks from occurring.
The differences between the V6 and V8 engines for the alternator replacement procedure are subtle. The alternator is located in the center of the engine. Some Explorers may have an engine cover that will need to be removed to access the alternator. The tensioner pulley on the V8 is moved clockwise instead of counterclockwise to release the tension. An alternator bracket and four bracket bolts will also need to be removed prior to removing and then replacing the alternator.