What was found
A/C RECEIVED MULTIPLE RIGHT JET PIPE OVERHEAT FAIL CAUTION AND RIGHT JET PIPE OVERHEAT WARNING MESSAGES IN FLT. PILOT RETURNED TO IAD FOR A LOGBOOK ENTRY AND IN ORDER TO HAVE MX INVESTIGATE. AIRCRAFT REMOVED FROM SERVICE LOOP B ON RH SIDE HAD AN MEL APPLIED TO IT LAST NIGHT. PILOT INDICATED THAT HE WAS ONLY USING LOOP A ON THE RH SIDE DUE TO THE MEL BEING APPLIED. MX PERFORMED OPS CHECKS AND DISCOVERED THAT LOOP B IS OPERATIONAL SO WE WERE ABLE TO CLEAR THAT MEL. LOOP A WAS THE ACTUAL FAULTY LOOP. LOOP A ON THE RH SIDE HAS BEEN PLACED ON MEL. R+R RH ENGINE JETPIPE A+B SENSING ELEMENT IAW AWAC SUPP 12-071C ANDM AMM26-11-04. PERFORMED ELECTRICAL TEST. TEST PASSED. REF. 264082/1 FOR ENGINE RUN TEST.