What was found
(CAN) DURING CRUISE THE ENGINE 2, ENGINE DRIVEN HYDRAULIC PUMP LOW PRESSURE LIGHT ILLUMINATED. THE ENGINE 2 IDG DRIVE LIGHT ALSO ILLUMINATED. THE CREW CARRIED OUT AN AIR TURN BACK. MAINTENANCE CARRIED OUT A FUNCTION CHECK OF THE ENGINE DRIVEN HYDRAULIC PUMP AND COULD NOT FAULT THE SYSTEM. THE IDG DRIVE LIGHT TROUBLESHOOTING DROVE THE REPLACEMENT OF THE IDG BUT THE FAULT STILL REMAINED. A FAULT WAS FOUND WITH THE IDG HARNESS. A NEW HARNESS WAS ORDERED AND WILL BE INSTALLED PRIOR TO RETURNING THE ACFT TO SERVICE.