Your battery might start your Toyota or Scion, but an original alternator you can depend on is what keeps your vehicle running. Your factory alternator does that best. Its job is sending consistent power between your car battery and the rest of its electrical systems. However, even high-quality Toyota and Scion alternators can go bad. There are signs, but alternator failure usually happens without warning. Symptoms include headlight flicker, inconsistent car radio or entertainment system operation, and a burning smell from your battery or alternator. The worst case is electrical failure. You might also see a dashboard alternator warning light or hear engine squeaking. A dead battery can also point to alternator trouble, and you can even cause alternator failure accidentally, with an incorrect jump-start or accessory install. The result: nearby auto parts can wear out or get damaged, especially if your alternator belt is too tight or your alternator is leaking fluid. Seeing the signs? Do an inspection, followed by a charging system test. Luckily, when to change an alternator isn't complicated: they last anywhere from 80,000 to 150,000 miles. That's around 7 years. The best alternator for that repair? Go OEM. An alternator made by Toyota & Scion is guaranteed compatible with your vehicle. Order one online from our auto parts counter today and you'll have the project done in no time!