A Line Mechanic reports he failed to apply heat shrink material to a P6 Canon plug connector that was part of a # 2 engine P2.7 inter-compressor Bleed Off Valve replacement procedure he had accomplished on a DHC-8-Q400.

Narrative

Received a turnover report from Swing shift on a Pilot report Write up on a DHC-8-Q400 (#2 engine TQ; FF; ITT split). Swing shift had already ordered the P2.6 valve and printed out the removal and installation Task from the Q400 AMM. Mechanics were going to replace the valve but were working on another task. My task was to remove and replace the P2.7 Inter Compressor bleed off valve. The aircraft was parked at 4-spot for Maintenance work. I did the removal and installation of the valve; but neglected to further research Task 75-31-01-400-801 which calls for installing the Cannon connector P6 with heat shrink. It was later brought to my attention that night; that there was a Supplement to be followed for the installation of heat shrink. This Supplement was given to me by another Mechanic; after my discussion with Day shift Lead if I had applied heat shrink to the Cannon plug.During Turn-over report to Day-shift Lead; I was asked if the P6 Cannon plug had heat shrink applied and I answered 'No' and when asked if there was heat shrink applied prior to my removing the P2.7 valve; I replied 'No there was not any heat shrink on the Cannon plug when I removed it.' I told him that I would return to the aircraft and install the heat shrink and he replied to me not to do so; as he would take care of it if need be. I had thought that since there was no heat shrink on the cannon plug when I removed it then there was not supposed to be any applied when I installed the Cannon plug P6. I failed to research a Reference Task on the installation of a Cannon plug which calls for installation of heat shrink. This is in the Task for installing the P2.7 valve: 75-31-01-400-801. It is my understanding that another Mechanic applied the required heat shrink to the Cannon plug after my shift ended and I had gone home. Place a statement in the AMM in the step procedure for connecting the Cannon plug; or a following step stating that heat shrink needs to be installed in accordance with (IAW) heat shrink Supplement. Also the Task 70-00-15-400-801 mentions that applying heat shrink is 'optional'.