As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT PACK LIGHT ON. ACFT GROUNDED. CONFIRMED LT PACK LIGHT ILLUMINATED WHILE RUNNING WITH APU (ENG OFF) AND LT THROTTLE ADVANCED, BUT INTERMITTENTLY. TROUBLESHOT TO OVERHEAD AIR CONDITIONING MODULE. REPLACED MODULE IAW AMM 21-51-65. PACK LIGHT REMAINS EXTINGUISHED.