Contrary to popular belief, the alternator (not the battery) powers the Isuzu Rodeo's accessories. When the alternator goes bad, you must replace it or the automobile will just sit. The replacement process is not difficult, and you can do it yourself, whether or not you have experience working on automobiles. It will take you about an hour to do the project, so save your money rather than giving it to the repair shops.
Pop the hood on the 1999 Isuzu Rodeo and disconnect the negative cable from the battery using a wrench to loosen the terminal nut.
Unplug the voltage regulator harness from the alternator. Remove the other electrical wires by loosening the nuts with a wrench.
Turn the adjusting bolt on the alternator counter-clockwise with a socket and ratchet. When the belt is loose enough, pull the belt off of the pulley.
Remove the alternator mounting bolts using a socket and ratchet, and pull the alternator out of the Rodeo.
Put a new alternator in the vehicle and tighten the bolts with the socket and ratchet. Put the belt on the alternator pulley. Tighten the tension on the belt by turning the adjusting bolt clockwise until you reach the proper tension. The belt is at its proper tension when you are able to depress it about ¼-inch with your finger.
Plug the voltage regulator wiring harness into the alternator. Connect the alternator wiring using a wrench to tighten the nuts. Connect the battery cable and tighten the terminal nut with a wrench.
