Your 2001 Mitshubishi Eclipse failing to start after a battery replacement for a variety of reasons. If the battery was not the original cause, or the only cause, for the vehicle not starting properly, you may be having problems with the electrical system, starter, ignition switch or a number of other potential components. Knowing a little about how vehicles and their starting systems work can help you make a diagnosis of the problem with your Eclipse.
Open the hood on your 2001 Eclipse, and inspect the new battery and its connections to the battery cables. If the battery cable eyelets have become corroded, the electricity stored in the battery will not be able to travel to the starter motor. Pour soda water over the terminals, and wipe them clean with a rag.
Wriggle your battery cables to ensure they are connected to the car battery properly. A tower will often try this trick first to get a car working again. If the battery cables have become loose, tighten them with a socket wrench.
Change the spark plugs on your engine if you have not had them serviced in a long time. If your spark plugs are new, you can have much of your electrical system tested at an auto parts store. Parts to check include your distributor and ignition system wiring as well as your alternator, although if you have just installed a new battery, a bad alternator will not prevent the Eclipse from starting. However, keep in mind that a bad alternator will only allow the vehicle to last 20 to 30 minutes of drive time.
Turn on your 2001 Eclipse. If the vehicle does not make any sounds of normal turnover, except a slight whirling sound and a click, your starter motor is likely not working properly. The starter is located on the lower right side of the valve cover, which is located front and center of the Eclipse engine. Disconnect the negative battery cable from your Eclipse. Remove the starter motor heat shield with a socket wrench, then remove the two bolts connecting the starter to the flywheel. Have the starter bench tested at an auto parts store, which can test the viability of the electrical parts of the starter as well as the mechanical components. If the starter does not pass the bench test, install a new starter into the Eclipse.
