Here’s how to figure out if your vehicle’s alternator has gone bad, plus all of the steps you’ll need to learn for how to replace it.

Testing indicated output was below specs due to a bad diode and other issues. While replacement alternators are readily available, keeping the original date-coded unit is desirable for restorations.

“They can easily miss an alternator with a bad diode that has lost performance, but because the loads are so small, everything looks fine.

Learn more on how long do alternators last. Our team of experts prepared the guide on everything you need to know on the lifespan of alternators.

You can replace the diodes in the alternator fairly easily, or just swap in a rebuilt alternator if one is available fairly cheaply for your car.

Six diodes are used in an alternator. Three of these diodes have "positive polarity" and are mounted on a heat sink that's called a positive rectifier assembly.

The alternator generates electricity to recharge the battery and run other devices. Chrysler investigators traced the problem to heat fatigue in an alternator diode.

When your car's alternator begins to fail — or has already failed — there are certain warning signs that you can expect to see along the way. But do you know what they are?