Return to Answer

If you have a voltmeter installed, a failed alternator will cause it to read ~12V (or ~24V) while a working alternator should show ~14V (or ~28V)

The voltage regulator (wired in after the alternator) outputs a voltage higher than the nominal battery voltage so that the battery can charge. If the voltmeter reads the nominal battery voltage it may indicate a failed alternator. It can also indicate a bad voltage regulator.

Depending on the type of ammeter you’re aircraft is equipped with it may show discharge vs charge current in which case a discharge indication could indicate a failed alternator or an alternator that can no longer supply the required current to operate all of your electronics and you are operating at a loss.

Lots of good info here if you are curious.

If you have a voltmeter installed, a failed alternator will cause it to read ~12V (or ~24V) while a working alternator should show ~14V (or ~28V)

The voltage regulator (wired in after the alternator) outputs a voltage higher than the nominal battery voltage so that the battery can charge. If the voltmeter reads the nominal battery voltage it may indicate a failed alternator. It can also indicate a bad voltage regulator.

Depending on the type of ammeter your aircraft is equipped with it may show discharge vs charge current in which case a discharge indication could indicate a failed alternator or an alternator that can no longer supply the required current to operate all of your electronics and you are operating at a loss.

Lots of good info here if you are curious.

If you have a voltmeter installed, a failed alternator will cause it to read ~12V (or ~24V) while a working alternator should show ~14V (or ~28V)

The voltage regulator (wired in after the alternator) outputs a voltage higher than the nominal battery voltage so that the battery can charge. If the voltmeter reads the nominal battery voltage it may indicate a failed alternator. It can also indicate a bad voltage regulator.

Depending on the type of ammeter you’re aircraft is equipped with it may show discharge vs charge current in which case a discharge indication could indicate a failed alternator or an alternator that can no longer supply the required current to operate all of your electronics and you are operating at a loss. If your aircraft only had a load meter you may not be able to determine anything but total consumption.

Lots of good info here if you are curious.

If you have a voltmeter installed, a failed alternator will cause it to read ~12V (or ~24V) while a working alternator should show ~14V (or ~28V)

The voltage regulator (wired in after the alternator) outputs a voltage higher than the nominal battery voltage so that the battery can charge. If the voltmeter reads the nominal battery voltage it may indicate a failed alternator. It can also indicate a bad voltage regulator.

Depending on the type of ammeter you’re aircraft is equipped with it may show discharge vs charge current in which case a discharge indication could indicate a failed alternator or an alternator that can no longer supply the required current to operate all of your electronics and you are operating at a loss.

Lots of good info here if you are curious.

If you have a voltmeter installed, a failed alternator will cause it to read ~12V (or ~24V) while a working alternator should show ~14V (or ~28V)

The voltage regulator (wired in after the alternator) outputs a voltage higher than the nominal battery voltage so that the battery can charge. If the voltmeter reads the nominal battery voltage it may indicate a failed alternator. It can also indicate a bad voltage regulator.

Depending on the type of ammeter you’re aircraft is equipped with it may show discharge vs charge current in which case a discharge indication could indicate a failed alternator or an alternator that can no longer supply the required current to operate all of your electronics and you are operating at a loss. If you aircraft only had a load meter you may not be able to determine anything but total consumption.

Lots of good info here if you are curious.

If you have a voltmeter installed, a failed alternator will cause it to read ~12V (or ~24V) while a working alternator should show ~14V (or ~28V)

The voltage regulator (wired in after the alternator) outputs a voltage higher than the nominal battery voltage so that the battery can charge. If the voltmeter reads the nominal battery voltage it may indicate a failed alternator. It can also indicate a bad voltage regulator.

Depending on the type of ammeter you’re aircraft is equipped with it may show discharge vs charge current in which case a discharge indication could indicate a failed alternator or an alternator that can no longer supply the required current to operate all of your electronics and you are operating at a loss. If your aircraft only had a load meter you may not be able to determine anything but total consumption.

Lots of good info here if you are curious.