What was found
ON CLIMBOUT AT 10,000 FT, CROSSFEED IN TRANSIT LIGHT STARTED COMING ON AND OFF INTERMITTENTLY. CONTINUED TO DO SO IN CLIMB. RECYCLED CROSSFEED VALVE AS CENTER FUEL ALMOST GONE. LIGHT STOPPED FLASHING. ACFT GROUNDED. CURRENTLY SYSTEM WORKS BUT DURING COURSE OF TROUBLESHOOTING FOUND MANUAL OPEN/CLOSE LEVER ON ACTUATOR EXTREMELY STIFF COMPARED TO NEW VALVE ACTUATOR. REPLACED ENGINE FUEL CROSSFEED ACTUATOR IAW AMM 28-22-21-000-804 AND 28-22-21-400-804. GROUND FUNCTIONAL CHECK GOOD IAW AMM 28-22-21-710-801.