What was found
CLIMBING THROUGH 17K, UNCONTROLLED HEAT IN EXCESS OF 100 DEGREES THROUGHOUT CABIN & COCKPIT. PAXS AFFECTED. TEMPS STARTING TO RISE IN AUTO, SWITCHED TO MANUAL, NO HELP. BOTH PACKS ON, SWITCHED OFF RT PACK, STILL NO HELP. PILOT FOLLOWED CHECK LIST, STILL NO RESPONSE. ACP FIM 21-61-00-810-849. REPLACED LT PACK PRIMARY & SECONDARY TEMP CONTROL VLVS. TEST FLIGHT REPORTED AS GOOD BY FLIGHT CREW.