Rear lights wiring

[Hoey]

Bailey Pageant Auvergne series 5 2006.
It had a broken nearside rear light cluster, purchased a replacement with reversing light and when fitting it I found an extra wire yellow with black strip which I thought was the reverse light connection but it appears to have no power. When I checked under the consumer unit for where the grey cable comes in the yellow wire for the reversing light was cut short and not attached to anything. Does anybody know what this yellow wire with black strip was for or where it comes from. (Just for information the yellow wire with black strip is also behind the offside light cluster)

 

[toad a caravan]

Is there any 12v fuses dedicated to the rear light assembly?

 

[toad a caravan]

Also have you 2 plugs or one 13 pin plug

 

[Hoey]

Have 2 plugs black and grey.
On my consumer unit I have 2 fuses both 15 which I have assumed are for inside lights. Will check in morning if both are for inside lights.