I have an 2002 Cavalier Z24. I recently brought it in for repairs. The Technician replaced the ECM/PCM and it's still acting the same way....the alternator just won't charge the battery. it's a new battery and a rebuilt alternator. Help???

Hey Joe , The first thing to do would be check for battery voltage on the heavier gage wire on the back of the alternator , if there is no voltage here there is a open circuit ! Which means the fusible link fried . This wire comes from the starter ! This charging system is controlled by the PCM , but they are rarely the problem . Do you have the charge indicator lit on the dash ? Do you have a check engine light on ? This system can set DTC'S - diagnostic trouble codes !
DTC B1328 DTC P0562 DTC P0563 DTC P0621 DTC P0622
.