Replace alternator with incorporated regulator

[silvius]

Hi, I would like to replace my alternator ( toyota 27030-56080 24V 25A ) with one ( 24V 35-50A ) with incorporated regulator.
I found an alternator with incorporated regulator and it has only 2 wires. ( S and F )
how should i connect it and what changes should i make?
One wire to +battery before fusible link ? S or F wire ?
I attach my wiring diagram,

thank you very much

 

[lacalvette]

Internal VR should have at least S and IG

 

[george_tlc]

What each of the 2 wires are called is dependent on the alternator naming convention being used.

Essentially the 2 wires will be ->

S (Sense):
The Sense wire (it goes to the battery so the alternator can sense the voltage for the regulator to do its busines). This wire goes direct to the battery (via a fusible link etc). No other loads on the fusible link (fuse etc) since it needs to accurately sense the battery voltage at the Battery+ post.

F or L or ... (Field, Light, ...)

This wire goes to the Alternator Light on the dash. The other end of the Alternator Light goes via the Ignition switch to Battery+. It's purpose is to provide initial field excitation for the Alternator to 'boot up'. During that pre-'boot up' time, the Alternator Light will illuminate with the key at the 'On' position. Once the Field starts up (alternator spinning), +12V comes OUT of the Field post and since the other end of the Alternator Light is also at +12V, the bulb goes out, unless of course the alternator is faulty. The Alternator Light needs to be an incandescent bulb to ensure sufficient current can flow through it to provide the Field Excitation, don't use an LED.

Your external regulator will have lots of connections, but there will be a Sense and a Field, you just need to identify them in your EWD. From you wiring picture, it would appear that your old alternator W-L wire is the Sense. And B-Y on the regulator will be you IGN+ to connect to the Field of your new alternator. It doesn't appear from the wiring snippet you posted that there is a Alternator Light??

cheers,
george.

 

[lacalvette]

Internal VR does not have F since field is the output to brush/slip rings. That is why you shouldn’t find F on internal VR alt.

Both type of VR need a ext (batteries) source IG and both have a sense S wire.
On those alt light L is optional and come from an independent source, neutral point of the star configuration on the stator.

 

[george_tlc]

^ It can still be called F since it connects to the bulb and can be the excitation point, i.e. even with an internal regulator it still needs power to start the field up to get the alternator running. I have an internal regulator alternator and the 2 pins are certainly named F and S right on the alternator. On that alternator, S is the sense to the battery and F connects to the Bulb as I wrote above. And I used it to retrofit an original external regulated alternator setup.

There are more than one naming convention on internal regulated alternators....

cheers,
george.