How to Replace the Alternator in a Jeep Wranglerby Jody L. Campbell
The alternator in a Jeep Wrangler is the heart of the electrical system. The battery provides electrical current to crank the starter -- after that, the alternator powers the engine's electrical components and recharges the battery. If the alternator breaks down, the electrical power to the engine is drawn from to the battery. Because the battery is only a temporary source of electrical power, it doesn't take long for a running vehicle, including a Wrangler, to run out of juice if the alternator fails.
Disconnect the negative battery terminal from the battery by using a hand wrench to loosen the connection clamp.
You next have to remove the drive belt from the alternator pulley. Locate the serpentine belt tensioner and use the serpentine belt tool to relieve tension on the belt. Turn the tensioner clockwise until there is enough slack in the belt to slide the belt off of the alternator pulley. Do not remove the belt completely unless you're replacing it. Some older Jeeps may have an alternator pivot bolt to loosen and then pivot the alternator on the bracket to relieve tension on the belt.
Remove the two alternator mounting bolts using a ratchet wrench.
Unsnap the B+ terminal cover if equipped on the back of the alternator. Remove the B+ terminal retaining nut with the ratchet and a socket. and remove the terminal from the alternator.
Unplug the other wires from the alternator, making careful note of where and how they connect. It may be useful to take a picture with your digital camera, or sketch out the wiring diagram, before removing the wires.
Pry the alternator out of the alternator bracket with a screwdriver.
Position the new alternator onto the alternator bracket and reverse the procedure to reinstall.
- The two most common engines in the Wrangler is the 2.5 liter 4 cylinder and the 4.0 liter 6 cylinder. The alternator sits on different sides in each engine option. The 2.5 liter places the alternator on the upper right hand corner of the engine (facing the Wrangler, this would be the driver's side) and the 4.0 liter places it on the upper left hand corner (the passenger side when facing the engine). The procedure for replacing the alternator is the same on both engines, but the routing of the drive/serpentine belts is different. Be sure to reroute the alternator belt correctly. Refer to the belt routing diagram in the engine compartment or, if one is not available, purchase a service manual for the Wrangler.