Hi Richard - fuse 17 is intact. But I did check out the wires - nothing apparent although each connection point was wrapped in tape. After unwinding the tape, all connections seemed fine. All of the wire ends into the black plastic connector seemed to be intact. Clicked the black plastic connector back into attachment point on the lamp housing unit and screwed the housing back in place on the car. Felt very disappointed that nothing seemed untoward. Was considering what to do next and while mulling over this, I switched on the lights to confirm the status quo and VOILA - the lamps in the left lamp unit have returned to functioning. Upon reflection, I felt an extra sense of "click" when the black connector was reattached to the lamp housing, so perhaps this was the basis for the fault - I remember having had to brake very suddenly not long before the issue was noticed. Maybe a very slight disconnection had occurred?? Who knows, but I ain't going to remove the housing anytime soon to try and do some experimental verifications of this!!! Thanks again to you and all contributors for your advice and suggestions.