A CANADAIR CL600 WAS DISPATCHED IN NON COMPLIANCE WITH THE R ENG TAILPIPE OVERHEAT SYS INOP WARNING LIGHT ON CONTINUOUSLY.

Narrative

I ARRIVED TO PREFLT ACFT FOR ZZZ-ZZZ1 REVENUE SVC. MAINT WAS AT ACFT TRYING TO REPAIR THE ENVIRONMENTAL CTL SWITCHING MECHANISM WHICH THEY COMPLETED AND CLRED THE RESPECTIVE MEL. WHEN THEY RE-POWERED ACFT; THE 'R JETPIPE OVERHEAT' WARNING WAS DISPLAYED ON EFIS. THE MECH WENT BACK TO ENG COWL AND MESSAGE WENT AWAY. WHEN HE RETESTED IT; THE MESSAGE CAME BACK. MY FO AND I ASKED THE MECH ABOUT THE MESSAGE AND HE SAID THIS WAS RELATED TO A WRITE-UP FOR THE 'R FIRE FAIL' LOOP DETECTION SYS ON THE R ENG. THIS SEEMED UNUSUAL TO MY FO AND MYSELF AND WE DISCUSSED IT. I WAS CONVINCED THAT THIS SYS -- THE JETPIPE OVERHEAT LOOP; WAS RELATED TO THE FIRE LOOP ON THAT ENG BASED ON WHAT THE MECH SAID. WE SUBSEQUENTLY DEPARTED ZZZ AND FLEW ZZZ1; THINKING THIS WAS AN MEL'ED ITEM THE CAPT WROTE UP THAT PREVIOUSLY FLEW THE ACFT. THE CAPT WHO TOOK THE ACFT FROM ME IN ZZZ1 DISCOVERED THE DISCREPANCY -- SAYING THIS WAS A SEPARATE WRITE-UP. IT TURNS OUT THIS IS A GNDING ITEM. I MISTAKENLY RELIED ON THE MECH'S EXPERTISE TO MAKE A GO DECISION AS PIC AND THE 3000 HRS THE FO HAD IN TYPE VERSUS MY 250 HRS.