The alternator on the 2001, 2002, and 2003 Ford Windstar can be compared to a pacemaker, with the battery of the minivan being the heart. The alternator regulates and provides electrical current that tells the battery how much voltage to distribute throughout the vehicle. Fortunately for you, this is not open-heart surgery, and the alternator in the 2001 through 2003 Ford WIndstar is much easier to replace than a heart.. A couple of simple tests with your multimeter will show you if your alternator is the cause of your problem, and replacing the alternator is nearly as simple.
Start the engine in the Windstar, and then pull the hood release. Raise the hood and set the hood prop. The alternator is in plain view, as it is the forward topmost unit attached to the passenger side of the engine. Use a multimeter to measure the voltage from the alternator. Turn the multimeter to “V” or volts setting. Set the multimeter in the center of the radiator upper support, so that it does not get near the rotating belt or pulleys.
Insert the positive lead from the multimeter onto the “B+” terminal of the alternator, which has a red plastic end surrounding the terminal and wire. Insert the black ground lead from the multimeter onto the casing of the alternator, or directly to the top of the engine block, near the upper intake. Do not use the upper intake as a ground point, as it is not metal and does not conduct electricity. If the meter reading for the alternator is less than 14.10 to 14.70 volts, replace the alternator.
Turn the engine off to begin replacing the alternator. Remove the negative battery cable from the battery, using a ratchet and a socket to loosen the cable end. Tuck the battery cable to the side of the battery so that there is no chance of accidental contact during this procedure.
Insert the 3/8 inch-drive square head on the serpentine drive-belt tool into the provided square notch in the tensioner assembly body. The tensioner assembly is built into the drive-belt system, and it resembles a metal “teardrop” with a single pulley at the outermost end. Rotate the tensioner assembly counterclockwise to release the tension on the drive-belt. Remove the drive-belt from the alternator pulley only, so that you do not have to reroute the entire belt.
Remove the clip-style electrical connector from the alternator, using a flat-head screwdriver to release the locking tab if needed. Do not pull the wires when removing either connector. Grab the wire connector ends only, so that you do not sever the very thin gauged wires. Remove the post-style electrical connector, using a ratchet and socket to remove the wire retainer nut. Remove the wire connector once you have removed the nut, and push the wire out of your way.
Remove the three alternator mounting bolts, with the ratchet and socket. Remove the alternator upward from the alternator bracket, using a small pry bar to assist you if needed. Install the new alternator into the alternator mounting bracket in the same position that you removed the old alternator from. (Hint: The bolt holes will not line up between the alternator and bracket if you have it in wrong.) Insert the alternator mounting bolts, and tighten them all between 30 and 41 foot-pounds, using a torque wrench and a socket.
Install the electrical wire onto the wire post, and tighten the wire retaining nut until it is snug. Do not apply torque to the wire post or you will break the post and ruin the new alternator. Install the clip-style electrical connector, and push it into the recessed alternator electrical socket until it clicks and locks into place.
Rotate the serpentine drive-belt tool counterclockwise with the tensioner assembly, and install the drive-belt on the alternator pulley. Do not place your fingers between the belt and the pulley when you have the tensioner compressed. Loss of control on the belt tool could result in injury or pinched fingers. Release the drive-belt tool slowly, once you have installed the drive-belt. Visually inspect the belt to make sure it is centered on each engine pulley, using a flashlight if needed. Rotate the tensioner assembly slightly counterclockwise to make any centering adjustments to the belt. Install the negative battery cable onto the battery post, and tighten the cable end until it is snug. Remove all tools from the engine compartment prior to starting the Windstar.