What was found
WHILE CRUISING AT FL350 A MASTER WARNING LIGHT ILLUMINATED, THE CABIN PRESSURE LIGHT WAS ALSO ILLUMINATED. BOTH THE CAPTAIN AND FIRST OFFICER COMPLETED THE IMMEDIATE ACTION ITEMS FOR A CABIN PRESSURE WARNING, THEN COMPLETED THE COM PROCEDURE FOR THE WARNING. PRESSURE WAS NOT RESTORED. 2/19/2025 - MX TROUBLESHOT AND TESTED ON GROUND LOG PAGE 77904 PRESSURIZATION SYSTEM OPS CHECK GOOD ON GROUND. WHILE PASSING THROUGH FL235 A MASTER WARNING LIGHT ILLUMINATED, THE CABIN PRESSURE LIGHT WAS ALSO ILLUMINATED. WE STOPPED THE CLIMB AT 240. BOTH THE CAPTAIN AND FIRST OFFICER COMPLETED THE IMMEDIATE ACTION ITEMS FOR A CABIN PRESSURE WARNING. PRESSURE WAS NOT RESTORED. THE FO THEN ADVISED ATC THAT WE WOULD REQUIRE A DESCENT TO 10,000FT. ATC CLEARED US TO 10,000 FEET WITHOUT DELAY. THE IMMEDIATE ACTION ITEMS AND COM PROCEDURES FOR EMERGENCY DESCENT WERE COMPLETED DURING THE DESCENT. 3-5-2025 LOG PAGE 77907 MX FOUND LOOSE AND DAMAGED CONNECTOR AT RH ACM COMPRESSOR DISCHARGE TEMP SENSOR. R&R CONNECTOR PER DC9 SWPM 20-31. OPS CHECK PRESSURIZATION SYSTEM IN AUTO AND MANUAL MODE PER DC9 AMM 21-32. ALL OPS CHECKS GOOD ON GROUND.