What was found
AT FL 370 DURING CRUISE, THE LT PACK LIGHT ILLUMINATED. OBSERVED A DROP IN LEFT DUCT PRESSURE AND A NOISE REDUCTION. LT PACK TEMP INCREASED FROM APPROXIMATELY 20 DEGREES C TO 40 DEGREES C. ACCOMPLISHED QRH AND PACK CAME BACK ON, LIGHT RESET. PACK TEMP DROPPED BACK TO 20 DEGREES C AND DUCT PRESSURE RETURNED TO 30 DEGREES. PSI MATCHING THE RT SIDE. ACFT GROUNDED. THE LT RAM AIR DOOR WAS CLOSED. SHOULD BE IN FLIGHT OPEN POSITION. FOUND TWO CIRCUIT BREAKERS ON THE P6-4, PULLED & COLLARED A4, A8, THEY SHOULD NOT BE COLLARED. REMOVED COLLARS & AND RESET THE CIRCUIT BREAKERS. CHECKED GOOD. RAN LT AND RT PACKS , OUTLET TEMPS MATCH AT 15 DEGREES C.