That is your stock alternator and Yes it's French

 

do you want to tell us what was happening with the charging system? Charging faults and issues with the car not having enough voltage are not always the alternators fault.

 

Ive posted this several times, dispite the objections of some people here who think they might be able to help you more than I can. This is straight from my involment in my last 2 years at GM with factory engineering field support.

AS I have posted many times:

The L-terminal circuit from the generator is a discrete circuit (a discrete circuit has no splices and only one source and destination) into the PCM. The PCM applies ignition voltage to the generator L-terminal circuit. A small amount of current flows from this circuit through the generator windings to ground to create a magnetic field which starts the generator process. When the generator is at operating speed and producing voltage, a solid state switch for the L-terminal circuit in the generator opens and the PCM detects that the initial startup current flow has stopped.

The PCM expects to detect low voltage on the L-terminal circuit prior to the generator rotating at operating speed and conversely expects the circuit to be at ignition voltage potential when the generator is operational. When the PCM detects a fault (circuit shorted to ground, or circuit shorted to voltage), the Driver Information Center will display Charging System Fault.

The generator has an input to the PCM called the F Terminal to indicate the percentage of total capacity that the generator is producing. This signal is detected by the PCM as a duty cycle from the generator and displayed on the scan tool as a percentage. The PCM can monitor the generators output under all conditions to determine if it is functioning normally.

When there is low demand from the electrical system on the generator, a low duty cycle percentage will be displayed. As more accessory load is placed on the generator, the duty cycle output detected by the PCM will approach 100 percent. A normally functioning generating system will never reach 100 percent as indicated on the scan tool.

The L and F terminals are the red and grey

Understanding this will help, also the alt/gen is in constant communication with the PCM, having the right alternator/gen -PCM link is important..... This charging system is Not your average charging system....

I hope this helps.
Bill aka ET

 

Or you can try this. According to this DIY posting, the most common failure of the Valeo alternators is simply the brushes. Although he is describing this process for Audi and VW with Valeo-manufactured alternators, his experience on those units could probably be extrapolated to our Valeo alternators.

 

From what he's posted so far, the output voltage seems OK, I'm "guessing" that either the regulator is having problems or the monitoring circuitry is. Need to scope the output to see what that alternator is really doing. But the good news is that you have the right core!!

 

Actually, the OP has never posted anything about output voltage of his alternator on this forum. Hence why I was asking what his symptoms where so I could offer suggestions on troubleshooting the car.

The most common charging circuit failure is the connections to the solenoid.

 

So I took alternator to repair shop... Guy took it apart and said nothing's wrong with it.
Why do I think it's alternator? Because I literally had a brand new battery and 2 days later car was running at 10.8> volts.
Don't know what to do now

 

Did you get a charging system fault message?

I would recommend you check the wires at the starter solenoid. The battery cable goes to the solenoid and 2 wires from the alternator also go there, the large charging wire and a smaller voltage sensing wire. Each of the wires from the alternator also have a fusible link on the solenoid end. Make sure the terminal ends are clean. Also, pull (not too hard) and look along each fusible link to make sure they good. Each one is a piece of wire surrounded by a soft rubber insulation if they stretch the wire inside is broken.

Bill Curlee has posted lots of excellent documentation to help troubleshoot and repair the electrical in a C5. This post shows what to look for in a connector. This is a wheel speed sensor harness connector and not the alternator but you're looking for the same type of damaged terminal end problem.

http://forums.corvetteforum.com/1554253292-post143.html

There might actually be a post from Bill about the solenoid connections in that thread, I just don't recall seeing it.

 

Yes I got the charge system fault and the low voltage messages