04 Pontiac aztek starts here and there

Pontiac Aztek If all electrical connection are Ok it needs to be scanned for codes.. BUT a vary common issue with Pontiac is the BCM body control module is the electrical system behaving fine? lights, windows, and all other controls? If there Ok preform a volt drop test on the starter circuit. It will "find" the problem. Alternator test, use a multimeter on the battery terminals if you get it to start output at idle should be 13.4-14.8 volts ok

Had everything tested battery isn't putting out enough voltage to start her car yet the battery is less then 6 months old and they told her they Fintry have a warranty on it and they don't have any side post batteries in until the end of next week which puts us in a bind because everyone else wants over 200 for the battery besides this place Which we can get it for led then 100 with out a warranty besides 90 day