Can a new alternator have a bad diode?

Can a new alternator have a bad diode?

Bad diodes are a common cause of alternator failure. The diodes are part of the rectifier assembly that converts the alternator’s AC output to DC. A leaky diode also can allow current to drain out of the battery through the alternator when the vehicle is not being driven.

Why does my car battery keep dying after I Turn Off the lights?

If you come back half an hour or an hour later, and things like the headlights are still on, that’s probably why your battery is dying. If you don’t see anything obvious, like headlights or a dome light left on, then the next thing to check is the battery itself.

How can you tell if your car battery is dead?

Check for these common symptoms of a dead battery: Are the dashboard lights dim? First, check the dashboard battery gauge. The battery should be giving a charge, even while the vehicle is off. If the dashboard lights are dim, something is likely wrong with your battery.

When to know if your alternator or battery is dead?

If the engine starts but dies immediately, your alternator probably isn’t keeping your battery charged. If a jump starts and keeps your car running, but the car can’t start again off of its own power, a dead battery is likely your answer.

Why does the battery light come on after the alternator is replaced?

This would make the Battery Light come on. It is also possible that there is a problem with the fusible link or the alternator fuse for the charging system.

If you come back half an hour or an hour later, and things like the headlights are still on, that’s probably why your battery is dying. If you don’t see anything obvious, like headlights or a dome light left on, then the next thing to check is the battery itself.

Can a battery be defective out of the box?

Sometimes, batteries are just not as good as they are manufactured to be due to hidden defects or a longer-than-usual shelf wait before being purchased. Similarly, alternators can be defective out of the box, especially if they’re refurbished or rebuilt.

What happens when a car battery is disconnected?

There can be more than twenty modules on each vehicle and many of these modules have some sort of “learned” memory, which may be lost when the battery is disconnected. This can cause something minor, like the clock to lose its time, but it can also lead to engine stalling or even a failed smog inspection.

Why does the battery warning light come on after replacing the alternator?

A relatively common “side-effect” of replacing a battery and/or alternator in a car is to have the voltage (battery) warning light come on. This is especially true in late-model vehicles with their more sophisticated internal diagnostic systems.