What was found
UPON ARRIVAL AT AIRCRAFT, FOUND ALL 3 TEMPERATURE SELECTORS IN THE OFF POSITION. AFTER APPLYING APU BLEED AIR PRIOR TO ENGINE START WITH APU ON, ZONE TEMP LIGHT ILLUMINATED ON CONTROLLER CABIN, CLEARED W/ MASTER CAUTION RESET. ACFT GROUNDED. REF FIM 21-62, TASK 801. RESET FAULTS ON LT & RT TEMP CONTROLLERS.