What was found
ON CLIMBOUT RIGHT PACK ILLUMINATED. RAN QRH AFTER COOLING DOWN PACK RESET. GROUNDED - YES. PERFORMED PZTC BITE, REF B737-900 FIM 21-62 TASK 801, NO FAULTS ON EITHER PZTC. REMOVED UNION FROM ACM TO INSPECT BLADES WITH BORESCOPE, NO DAMAGE FOUND. REINSTALLED UNION, IAW B737-900 AMM 21-51-04. PER FIM 21-52 TASK 821 AND DUE TO A/C RT PACK HISTORY, RECOMMEND HEAT EXCHANGER CLEANING, REF AMM 21-51-03-160-807. CLEANED RIGHT PACK HEAT EXCHANGER, REF AMM 21-51-03-160-807. RAN PACK FOR 20 MINUTES, OPS NORMAL. COMPLETED FIM TASK 21-52 TASK 821.