AL82 Alternator fault

Hi guys, I have an AL82 12v internal regulated alternator, the 12v feed through the idiot light is fine. When you start the car up the light goes out but not putting out any charge?

I pulled the brushers out and tested omhs resistance over the 2 slip rings and got 2.9. anyone know what this should read or any other tests i can do on it.

The rotor very rarely fails so 2.9 ohms sounds OK.

It's usually the diodes or regulator that go.

It could be a power diode defective.

Thanks for the info, any idea once I remove how to test these items?

Also, anyone know where i can buy a diode pack or reg for this alternator?

I bought a genuine internal reg through Amazon, $11.00, i was quoted $60.00 for a second hand one in Australia, i just googled the part number and they came up as available.
Is this the one you have, http://www.ebay.com.au/itm/Volkswagen-Beetle-Karmann-Ghia-Thing-71-79-Voltage-Regulator-BOSCH-9-190-087-003-/151105250535?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AVolkswagen&hash=item232e9324e7