it COULD be.. sure.
check your cable connections to the battery, and the grounds from the battery to the chassis, and the alternator to the chassis. also check for loose, frayed, or corroded cables, connectors, and terminations.
ALT TEST:
Check your battery voltage, as described in most of the alternator posts. car running, look for 14.0-14.7 or close
BATTERY test:
car off, surface charge removed (turn on interior and headlights for 60 seconds, look for 12.0 or higher.
