What was found
WING ANTI-ICE R VALVE ILLUMINATED TURNING ON WING ANTI ICE MASTER CAUTION-ANT ICE A FEW SECONDS LATER. LIGHT WENT OUT AFTER TURNING WAI OFF. CYCLED SWITCH AGAIN SAME RESULT LEVEL AT 5000FT 210 KTS. GROUNDED - YES. PERFORMED WING THERMAL ANTI ICE VALVE OPERATIONAL TEST WITH APU BLEED PNEUMATIC AIR REF. B737-9 AMM 30-11-11-710-801 CYCLED VALVE 3 TIMES FOR 5 SECONDS EACH TIME. OPS CHECK NORMAL. NO DEFECTS NOTED AT THIS TIME.