B737-800
Maintenance Airframe; Maintenance Powerplant
Situational Awareness; Troubleshooting; Workload
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Landed As Precaution; Flight Crew Diverted; General Maintenance Action; General Flight Cancelled / Delayed
Procedure; Human Factors; MEL; Aircraft
Working engine #1 cowl anti ice valve bright transit light; started to comply with MEL procedure to inoperative valve in open position. Aircraft was on a quick turn; while complying with MEL [I] was receiving other gate calls from multiple other aircraft with only two technicians working 8 gates. Proceeding to comply with MEL; [I] inadvertently disconnected [the] wrong connector as called out in MEL. Later; aircraft departed [and it was] discovered the anti-ice valve connector was removed. Called Maintenance Control and found aircraft diverted because of amber over pressure light illuminated. This is when we discovered the wrong connector was removed. Notified Maintenance Control and talked to Station Supervisor.
Technician reported disconnecting the wrong connector when complying with MEL procedures; causing a diversion and precautionary landing.