The alternator is the electrical component on your 1998 Cadillac DeVille that keeps the battery charged. Without an alternator, your battery would constantly lose its charge. If you have tested your battery to make sure it doesn't need to be replaced and it continues to lose its charge, it's time to replace the alternator. Replacing the alternator on your 1998 DeVille is a straightforward process that you can do yourself with just a few tools and a bit of time.
Park your DeVille on flat ground and engage the parking brake. Lift the hood and prop it open. Allow your engine to cool down completely. Disconnect the negative cable from the battery terminal and push it to the side of the battery.
Loosen and remove the two mounting bolts that secure the alternator in position. Rotate the alternator toward the V-belt, or drive belt, creating enough slack to remove it.
Remove the electrical wires from the back of the alternator. Use a pen or a marker to create identification marks to help you connect the wires to the new alternator.
Remove the alternator from the mounting assembly. Compare it to the new alternator to make sure that they are identical. Rotate the new alternator into position on the mount and against the V-belt until there is no obvious slack in the V-belt and the mounting bolts line up with the mounting assembly. Connect the electrical wires to the new alternator following the identification marks from the old one. Tighten the mounting bolts to secure the alternator in place.
Take your DeVille for a test drive of at least 15 miles. Check it a few hours later, and the next day as well, to make sure that the battery is holding a charge.
