As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND RIGHT PACK LIGHT ILLUMINATED ON PREFLIGHT. GROUNDED - YES. DISCOVERED CANNON PLUG ON RT TEMP CONTROL VALVE WAS NOT COMPLETELY SECURED. SECURED CANNON PLUG. RT PACK SYSTEM AND FAULT LITE OPS CK GOOD. REF B737-900 AMM 21-61-00-700-806-002.