What was found
ON CLIMBOUT OF PHX EN ROUTE FOR RNO RT WING TO BODY OVERHEAT LIGHT ILLUMINATED. COMPLIED WITH QRH BOOK PROCEDURES AND SYSTEM RETURNED TO NORMAL, THEN LIGHT CAME BACK ON, TURNED BACK TO PHX AND LANDED WITHOUT FURTHER EVENT. MAINTENANCE PERFORMED VISUAL INSPECTION OF RT AIR CONDITIONING BAY AND RT WING LEADING EDGE AREAS, NO DEFECTS WERE NOTED. RAN PACK WITH ENGINES RUNNING TO CLIMB POWER FOR 20 MINUTES, NO DEFECTS NOTED. AS A PRECAUTION REMOVED AND REPLACED ACCESSORY COMPARTMENT OVERHEAT CONTROL UNIT IAW BMM 26-10-02, OPERATIONAL CHECK WAS GOOD. BENCH TEST OF ACCY BAY OVERHEAT CONTROL UNIT WAS NO FAULT FOUND. PERFORMED SB 65-52808-26-01 REPLACING A2 & A4 MODULES, UNIT TESTED GOOD PER CMM 26-10-32, REV. 12.