What was found
PHX/SAN - FLT NR 19 - AIR TURNBACK, L2 DOOR WARNING LIGHT ILLUMINATED DURING CLIMB-OUT OF PHX. FLIGHT CREW VERIFIED HANDLE WAS ROTATED TOWARD OPEN, AND MANUALLY HELD HANDLE DOWN. AIRCRAFT RETURNED TO PHX, LANDING WITH FURTHER INCIDENT. MAINTENANCE CLEANED AND LUBED MICRO-SWITCH PLUNGER, AND CHECKED DOOR RIB IAW BMM 52-11-01 AND 52-11-00. CYCLED DOOR TEN TIMES, ALL INDICATIONS NORMAL. AIRCRAFT RETURNED TO SERVICE. (M)