Does anyone know….? The fiber optic cable to the amp in the boot….should both cables be lit? On mine, when unplugged, only one is lit. I am asking because I am getting ready to replace the amp and then I saw this and thought that may be the source of my problem with the door speakers. Thanks.

 

You need to understand the BOF D2B network..
My Training Guide .pdf from Jaguar Training when these cars were new.

 

Fibers are unidirectional. One fiber carries one direction, the other carries the other direction. The one that's lit is incoming for the connector you're looking at. The corresponding port to the dark fiber where you disconnected it should be lit on the connector's mate, the outgoing fiber at that junction.