Alternators use an engine's steady cycling to generate power for a vehicle's accessories, as well as to keep the vehicle's battery charged. These parts can go bad after time, requiring them to be replaced in order for a vehicle to continue starting and running properly. Replacing the alternator on a Mitsubishi Eclipse requires a few simple tools and 15 to 30 minutes of time.
Very carefully pull your Mitsubishi up on car ramps and put the transmission in park. Lock the emergency brake.
Open the hood and use a crescent wrench to remove the negative terminal from the battery.
Locate the alternator at the top of the serpentine belt assembly. Remove the electrical connection on the alternator using a 12 mm socket wrench.
Climb under the vehicle and locate the swing pulley near the bottom of the serpentine belt assembly. The swing pulley is smaller than the other pulleys in the assembly and is accompanied with a brass bolt end called the 'auto tensioner.'
Connect a crescent wrench to the auto tensioner and twist it counter-clockwise. This will let up pressure on the serpentine belt. While holding the auto tensioner, slide the belt off the swing pulley.
Access the alternator from the top of the engine carriage once again. Slide the serpentine belt off the alternator's drive.
Remove the three mounting bolts around the sides of the alternator with a 12 mm socket. Slide the alternator away from its mounting assembly.
Slide a new alternator into place and secure it with the three mounting bolts you just removed.
Slide the serpentine belt over the alternator's drive and climb under the vehicle.
Connect a crescent wrench to the auto tensioner once again and twist it counter-clockwise. While keeping pressure on the part, slide the serpentine belt back over the swing pulley.
Replace the electrical connection on the alternator.
Replace the negative terminal on the vehicle's battery.
