As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT PACK LIGHT ILLUMINATED WHEN MASTER CAUTION IS PRESSED. PACK LIGHT EXTINGUISHES WITH MASTER CAUTION IS PUSHED. GROUNDED - YES. PERFORMED PACK TEMP CONTROL BITE REF B737-800 FIM 21-62 TASK 801. NO ISSUES RT PACK TEMP CONTROLLER. L/H PACK TEMP CONTROLLER ON BIT AND PREV FLT GOT TCV THIS PACK. LIGHT WENT OUT ON VERIFY.