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.

It all starts with a few telltale problems: The battery light coming on for a brief moment, maybe dimmed headlights and a few flickering gauges. Perhaps your car even gives off an odd smell, or you ...

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

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.

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