ive just getting some st led lights for my focus but with mine been a pre facelift ive had to cut my loom to get them to work, they work fine but ive got a black wire spare and im not sure what to do with it, i wired the correct colours together blue to blue, green to green, orange to orange, but the standard loom had 2 black wires and the lights only one.
will it cause any problems leaving it loose or shall i wire it in with the other black wires, i imagine black wires will be the earth?
hes a pic of the st light wires, all the same colours but with a extra black wire, any ideas fellas?

 

Probably ok to leave it loose, what I would have done however is join them all together. As long as they are working then it should be fine.

 

Yeah they are working fine just don't wnna undo the wiring I've soldered, it's deffo an earth wire the old lights have two separate earths and the newer are wired a little different, I've been googling