MustangForums.com

Ford Mustang V6 2005-2014: How to Replace Alternator

A new alternator will fix a majority of your Mustang's power problems. This article will walk you through installing a new alternator.

By Jared Hammond - September 25, 2015

This article applies to the Ford Mustang 4.0L V6 (2005-2014).

Generally when you're having power issues and it's not the battery, then it's probably the alternator. A failing alternator can fail to recharge the battery or cause the headlights to flicker and dim, eventually it will cause starting issues as well. One way to quickly check your alternator is to check the voltage at the battery while the car is running. You should be getting between 13.8 and 14.2 volts through the battery, but if you see any fluctuations, then your alternator is probably close to failing. If your alternator is shot, then it's time to gear up for a replacement.

Materials Needed

  • Replacement alternator
  • Ratchet with 13mm and 15mm 3/8" deep sockets
  • 15mm box-ended wrench
  • Flat head screwdriver

Step 1 – Disconnect battery and air intake hose

Unbolt the negative cable (black) from the battery and set it aside. Use your flat head screwdriver to loosen the screw on the bracket of the large air intake hose. Slide the hose away from the throttle body. Then pull out the smaller vent hose next to the alternator.

  • Figure 1. Remove the air intake hose.
  • Figure 2. Vent hose and serpentine belt.

Step 2 – Remove the serpentine belt

Find the tensioner pulley below the alternator pulley. Insert your long 3/8" socket into the tensioner pulley and attach your box-ended wrench to the idler pulley next to it. Using the wrench to hold the pulley steady, turn the tensioner counterclockwise until the serpentine belt comes loose. Slip the belt off the alternator pulley.

Figure 3. Loosen the tensioner.

Step 3 – Remove old alternator

The alternator is held down by two 13mm bolts and a 15mm nut that you'll need to remove. The nut will require a deep socket. On the back of the alternator, you should see a wire harness and a red battery cable. Push in the clip on the wire harness to unplug it. Unbolt the battery cable. The alternator should be completely loose now and can be slid out from the engine compartment.

  • Figure 4. Unbolt the alternator.
  • Figure 5. Unplug the wire harness.
  • Figure 6. Remove the power cable.
  • Figure 7. Remove the alternator.

Step 4 – Install new alternator

To install the new alternator, simply reverse the previous steps:

  • Slide alternator onto the bracket.
  • Plug in wire harness.
  • Bolt down battery cable.
  • Tighten down nut and bolts.

Be careful when reinstalling the serpentine belt because it has to be exactly the same way it was before. If necessary, pull up a diagram and double check. Make sure that the belt is sitting flush on the pulleys. To tighten it, turn the tensioner clockwise. Reattach the vent hose and the air intake hose. Tighten the bracket on the air intake. Reconnect the negative battery terminal and then you're done.

Figure 8. Return the serpentine belt.

Featured Video: 2006 Mustang V6 Alternator Change

Related Discussions