battery not charging on signum

[superjetandy]

hi, my battery has stopped charging on my 2003 signum, ive replaced the alernator change the battery and checked all fuses but its still not charging. the battery light comes up on the dash when the battery is nearly dead. does anyone have any ideas what it could be, ive been told it could possibly be something to do with the ecu is that possible? any help at all would be great as im stuck with no car. thankyou.

[Jezzy]

Take it to a garage and get them to do a (free) test of the new alternator and battery.