Easy lifehacks

What does it mean if my battery light is red?

What does it mean if my battery light is red?

All cars today have an electrical system that uses a 12-volt battery to supply power when you drive around. The battery is charged by the alternator when you are driving. It’s when this system is not working correctly that the red battery light on your dashboard will light up to alert you to the problem.

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.

What should the charge voltage be on an alternator?

Turn on the high beams for 10 seconds and then turn them off. Measure battery voltage across the battery posts with your DMM. You should get between 12.4 and 12.6V. This means your battery is fully charged. If you get a reading below 12.4V, charge the battery before continuing. 5b. Measure the Charging System’s No-Load Voltage

What happens when the diodes in an alternator go bad?

Alternators use diodes to rectify alternating current produced by the alternator into direct current. When one or more diodes go bad, the alternator can cause all kinds of problems. AC voltage leak can cause your lights to dim and drain power from your battery, for example.

How can I tell if my alternator or battery is OK?

As with most electrical issues, if you know the battery or alternator is OK (because you had it tested), then diagnosis comes down to tracing and testing for continuity from one portion of the circuit (s) involved to the next.

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.

Turn on the high beams for 10 seconds and then turn them off. Measure battery voltage across the battery posts with your DMM. You should get between 12.4 and 12.6V. This means your battery is fully charged. If you get a reading below 12.4V, charge the battery before continuing. 5b. Measure the Charging System’s No-Load Voltage

Alternators use diodes to rectify alternating current produced by the alternator into direct current. When one or more diodes go bad, the alternator can cause all kinds of problems. AC voltage leak can cause your lights to dim and drain power from your battery, for example.

As with most electrical issues, if you know the battery or alternator is OK (because you had it tested), then diagnosis comes down to tracing and testing for continuity from one portion of the circuit (s) involved to the next.

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Ruth Doyle