The alternator on a 1993 Ford F150 light-duty pickup provides electrical power for the truck when the engine is running. The serpentine belt turns the alternator pulley, which spins the alternator's internal generator to produce the electricity. A voltage regulator ensures the alternator doesn't over- or undercharge the F150's systems. If either the generator or regulator malfunctions, you'll need to replace the alternator immediately. Anyone with basic auto-repair experience can replace the alternator on a 1992 Ford F150 in about an hour.
Open the hood and disconnect the negative battery cable end from the battery terminal with your battery wrench. Move the serpentine belt tensioner off the serpentine belt using the serpentine tool. Slide the belt off the alternator pulley with your other hand before slowly moving the tensioner back into place.
Unplug the alternator wiring harness from the back of the alternator manually. Unbolt the ground wire from the back of the alternator with the socket set.
Remove the alternator mounting bolts with a socket set. Lift the alternator up and out of the engine well by hand.
Compare the old alternator to the replacement unit. Make sure the pulleys are identical, the voltage regulators are the same, the bolt pattern is identical and the rear faces are identical before installing the replacement alternator. If there are any differences, take both alternators to your place of purchase to match the old one to an identical replacement.
Set the replacement alternator into the alternator bracket. Thread the mounting bolts in until they're finger tight and then tighten them fully with the socket set.
Plug the wiring harness back into the alternator. Bolt the ground wire to the alternator with the socket set.
Move the belt tensioner over with the serpentine tool, slip the belt over the replacement alternator pulley and then move the tensioner slowly back into position. Remove the serpentine tool.
Reconnect the negative battery cable to the battery in the reverse of how you removed it.
