What was found
BURNING ODOR NOTICED AFTER LANDING. PERFORMED FIM 21-22-815 FOR ODOR. RAN NR 1 & 2 ENGINES SPERATELY. AS NR 1 AND 2 PACKS ISOLATED, COULD NOT DUPLICATE ON GROUND. OPS OF PACKS NORMAL ON GROUND. OK TO CONTINUE. NO EVIDENCE OF ODOR. ON SUBSEQUENT FLIGHT FA REPORTED AN ODOR. PRIMARY STAB DRIVE RELAY IN FWD CARGO WAS FOUND BURNED. REMOVED AND REPLACED THE NOSE DOWN TRIM MOTOR RELAY IAW AMM 27-41-03-400-801. RAN TRIM MOTOR OPS CHECKED GOOD.