hi guys, I’ve been towing for a little while and my side lights don’t work on the trailer. Everything’s else works fine. I checked the car and there’s only 5 volts coming through. Unfortunately the wiring has been connected through scotch locks. But still the cars wiring only has 5volta through it. The cars an 2005 2.7tdi but it’s got the 2009 head and tail lights fitted. Is there a specific way the trailer lights need connecting to allow full 12volts to the side lights?