Locate the starter on the back of the engine while working from under the car. Remove the electrical connection at the back of the starter with a wrench and lay. Access our free Starter Repair Guide for Nissan Altima & Sentra through Starter location and mounting detailL engine; Nissan Altima & Sentra. The starter on your Nissan Sentra engages the flexplate that spins the engine on startup. The starter motor has a spinning shaft and gear that extends on.