'82 GS1100EZ Instrument wiring

[KBL]

Hi, I'm new to this site so please advise me if I am not following the proper protocols. I don't want to annoy anyone. Not even sure if I'm in the right space to ask for help. But here goes anyway. I am restoring, not rebuilding, the 82 GS1100EZ I bought new here in Canada. A crash destroyed my instrument cluster and I got a new(used) one from USA. My harness was equiped with a single 18 pin connector to cluster, the new one came with 2, 9pin connectors. No problem, rebuilt it with 2 deutsch connectors. However, my problem is I'm left with a brown/white wire for the "tail" lamp with no corresponding connection to harness. All the wiring diagrams I've seen show this wire runs from the lamp thru the connector to the check panel control unit but there is no Br/W wire in my harness. All other wires are accounted for. I've set up the harness on my bench with all lighting connected. Seems to work fine but of course the cluster tail lamp is inoperative . Anyone have any knowledge or advice that can help solve this issue.