Hello Scoobynet,
Please can someone advise me what might the problem with my 04 plate scooby wrx STI Prodrive?
The brake light & battery light have come on, I've replaced the battery and had the alternator reconditioned, but still the lights are on.
Test the battery it's reading 12volts, start the car it drops down to 11volts.
Any ideas would be much appreciated.

 

That doesn't sound right, it should read about 14v when the car is charging, what happens if you rev the engine a little.
Have you checked the connection on the alternator, make sure it's tight and is not broke.

 

As above its not charging at 11volts. Either the alternator is duff. Have you probed the back of the alt with a metre. Check the alternator has a good earth. The main live cable from alt to battery and probe the ind feed for voltage

 

Battery & brake lights still on, I've put a new alternator and battery on the car.
I've checked all the wiring?
Any other suggestions would be much appreciated?????

 

I've had this very same issue in my WRX 2003, the problem was a broken pin in the alternator green connector, so I believe any issue with the connector pins or alternator wiring may cause this.

Is the new alternator charging the battery and keeping the voltage above 13-14v?

Cheers.