Is this a 24V Alternator?

[Pearly]

Pardon my ignorance, but can you tell a 24v from a 12V alternator, just by looking at it? I can't find any 12V or 24V markings...

It came in a box-o-bits.

 

[fjbj40]

Have you tried cleaning the tag to see yet?

Otherwise the 12and24volt units look the same. It looks to be an internally regulated unit though.

Daryl

 

[Pearly]

The tag has been painted over. When I tried cleaning off the paint, it just strips the original paint off too.

 

[NoeyR]

Looks like a 12 volt due to the black plug as opposed to a green one. Maybe take it to an alternator rebuilder to check and confirm.
Attached is a pic of a 24v fine spline with green plug minus the vac pump.

 

[fjbj40]

Plug color makes no difference, my bj60 12 volt has a green plug, unless it has been changed.

Daryl

 

[Pin_Head]

It is the regulator that determines the voltage. Unregulated, they can put out over 100 V.

 

[lostmarbles]

It is the regulator that determines the voltage. Unregulated, they can put out over 100 V.

This statement implies that both 24V and 12V externally-regulated alternators are constructed the same Pighead.

And they aren't the same because Toyota uses different part numbers for each.

(So the alternators themselves are different too.)

 

[vosy]

Same

A lot of the time the only difference between the 12 and 24 volt alternators is the diode boards. We run 24 volt alternators on 12 volt aircraft no problem. 12 volt alternators on 24 volt aircraft cause a lot of comm noise but work fine.

 

[fjbj40]

A lot of the time the only difference between the 12 and 24 volt alternators is the diode boards. We run 24 volt alternators on 12 volt aircraft no problem. 12 volt alternators on 24 volt aircraft cause a lot of comm noise but work fine.

Why would you do this? If it is a 24 volt aircraft and you put on a 12 volt alt and vise versa then you are releasing an aircraft to service that is not in compliance to its certification!

Burning up diodes in radios would also be a problem putting 24 volt to a 12 volt aircraft.

Daryl

 

[Pin_Head]

This statement implies that both 24V and 12V externally-regulated alternators are constructed the same Pighead.

Hey, who are you calling a Pighead?

24 and 12 V automotive alternators are probably different internally in terms of the number of windings and the diameter of wire in the stator because the 24V one has to put out a higher voltage at low RPM than the 12V. This would not be an issue for an alternator that ran at a constant high RPM. We don't see very many 24V alternators here unless you work on military equipment.

I am just saying that they don't have to look obviously different, like a 24V one is twice as large. The simple and obvious way to determine its regulated voltage is to hook it up, spin it and measure the output voltate.

 

[Pighead]

Hey, who are you calling a Pighead?

^^^x 2

 

[lostmarbles]

This statement implies that both 24V and 12V externally-regulated alternators are constructed the same Pighead.
And they aren't the same because Toyota uses different part numbers for each.
(So the alternators themselves are different too.)..

Hey, who are you calling a Pighead?

^^^x 2

Ooops. Had to do it one day.

Pighead and Pinhead are just too similar to an old man who's lost his marbles.

Twas an honest slip ..... Really