The alternator in a Ford van is a generator that supplies all of the electricity that the van needs. It also charges the battery. Signs of a failing alternator are dimmed headlights, battery warning light illumination, and a whirling sound coming from the alternator itself. If you notice these conditions, you should replace the alternator.
Disconnect the cable running to the negative battery terminal using a socket wrench. Loosen the retaining nut on the clamp and slide it off the battery terminal.
Loosen the alternator pivot bolt. This is the top-most bolt on the alternator that holds it to an adjustable bracket.
Loosen the bottom mounting bolt.
If your Ford van uses a serpentine belt, release the tension on the belt by loosening the auto-tensioner. On most Ford engines, the tensioner is at the top-left of the front of the engine. It should be facing you if you are standing in front looking at the engine. Use a socket wrench and a Torx bit, and turn it counterclockwise to release tension on the belt. You may need to use a breaker bar to give yourself enough leverage. Ford almost always uses a 3/8-inch Torx bit for auto-tensioners.
Slip the belt off the alternator pulley. Do not remove the belt completely, and make a note of the belt orientation for when you reinstall the belt.
Unplug the electrical connector from the alternator. Squeeze the top of the electrical plug and pull the connector out of the back of the alternator.
Remove both the upper and lower alternator bolts.
Remove the alternator by pulling it forward and lifting it up.
Install the new alternator assembly. Installation is the reverse of removal. Make sure that when installing the belt, you center the teeth on the belt onto the grooves in the alternator pulley. Also, for auto-tensioned belts, make sure that you follow the belt path stamped on the frame of your van to the left of the hood latch.
Wedge a breaker bar between the alternator housing and the firewall for pivot bolt- type alternators. Apply tension on the belt while you tighten the pivot bolt to 40 ft-lbs with a torque wrench. Use a belt tension gauge to ensure that the belt tension is at least 50 lbs and no more than 150 lbs.
Tighten the lower alternator mounting bolt to 40 ft-lbs with a torque wrench.
Reconnect the battery and turn the ignition switch to "II". Start the van and check to make sure the battery light goes out.
