Self Exiting alternator

[LvR]

View attachment 247817So if this was the rectifier ( it will be similar) the exiter wire obviously goes to the plug input , do I need another 12v feed going into it too ? And does the earth go to the prongs ? Thanks

No idea since I do not have the actual thing in front of me.

The pictured thing is the regulator/exciter - diodes/rectifier is still inside the alternator body (way more substantial).

When you remove the regulator you should be able to figure out where the fat battery cable makes contact and where the alternator earth is made - YES you need BOTH in addition to the exciter plug there. Leave the carbon brushes alone and unconnected

 

[Donald]

A 3 wire alternator has sense (always sees voltage), excite (sees voltage when key is on) and output.

A single wire only has output. You need to rev it to a certain RPM (1200, maybe 1500) and that kicks it in and it will then charge even at idle.

 

[Nathan35]

No idea since I do not have the actual thing in front of me.

The pictured thing is the regulator/exciter - diodes/rectifier is still inside the alternator body (way more substantial).

When you remove the regulator you should be able to figure out where the fat battery cable makes contact and where the alternator earth is made - YES you need BOTH in addition to the exciter plug there. Leave the carbon brushes alone and unconnected

Ok thanks , I’ll take it apart at the weekend and see what I can figure out

 

[MolaKule]

Here is a three-wire alternator system showing the internal circuitry and how it is connected to the outside.

A "single-wire" system has only a body ground and a large wire to the battery, starter, and a feed to the rest of the electrical system.

Again, you need to consult the wiring diagram of your vehicle because some vehicles have LED indicators, whereas some of the older systems have an incandescent lamp. Why does it matter which type of indicator lamp you have? Because the LED type is voltage "polarity" sensitive. Furthermore, the indicator lamp may be controlled by your ECU (computer) via an isolation diode.

Until you figure that out, I would not try to wire anything to the lamp circuit.

 

[Nathan35]

Here is a three-wire alternator system showing the internal circuitry and how it is connected to the outside.

A "single-wire" system has only a body ground and a large wire to the battery, starter, and a feed to the rest of the electrical system.

Again, you need to consult the wiring diagram of your vehicle because some vehicles have LED indicators, whereas some of the older systems have an incandescent lamp. Why does it matter which type of indicator lamp you have? Because the LED type is voltage "polarity" sensitive. Furthermore, the indicator lamp may be controlled by your ECU (computer) via an isolation diode.

Until you figure that out, I would not try to wire anything to the lamp circuit.


View attachment 247862

Ok thanks this is the wiring diagram for the Alternator circuit which doesn’t mean a great deal to me tbh , I’m not sure where the light component sits in this diagram to try and tell what polarity it is , thanks for the reply .

 

[LvR]

View attachment 247957
Ok thanks this is the wiring diagram for the Alternator circuit which doesn’t mean a great deal to me tbh , I’m not sure where the light component sits in this diagram to try and tell what polarity it is , thanks for the reply .

The "light" component in the dash is an intelligent animal - it will probably not be shown on any diagram that we can access - it's being spoken to via the CAN bus in the dash computer where an instruction is received (from the ECU/BMS/BSS) to illuminate the thing - no simple direct lights to be accessed anymore like on the older vehicles.

Also - realise that is basically a Renault animal