Battery Light no Crank
 

I have a 2003 Alero. Strange problem, may just be the alternator.
Changed so far. Ignition key/assembly, Ignition Switch, Battery, cleaned all grounds and most of the ground concentrator tabs. Shorted the Nuetral Safety Switch
CODES V1000 V1096 B1369 B1379 B2752 separate run B1327 U1064. IPC fails to communicate some times. if I disconnect the battery ground I can get the IPC to light up, then it goes to Battery Light and get codes above. Love the car, don't want it to be parts, but need to figure this out soon. Noticed with a battery charger on it the DCV at the cig lighter goes up to 16.5 or 17 VDC. Is this a symptom of a bad regulator somewhere, or the alternator bad.
The battery is strong and can crank the car if i jumper on the starter solinoid. starts for 1 second then dies from no ignition and fuel pump shutoff by BCM.

Fuse block all check out except (pass side) no Cruise SW power, Cruise SW LPS, HVAC Blower, Cruise, Fog, Int LPS. it does have 15VDC on the radio batt fuse.
Driver fuse block no VDC on G (PCM ACC) I (IPC/BCM ACC) otherwise all the fuses have power. Power windows don't work.

Not sure what it could be. My car is doing a very similar issue but havent figured it out.

Are you getting spark?
One of the things that's hard to say over the internet. My best guess, start looking for ground where there shouldn't be.