Caravan brake lights not working

davetrfc
davetrfc Forum Participant Posts: 2
edited May 2015 in Caravans #1

Hi could anyone shed some light why we can't get the brake lights to work when we hitch up.  we have a dedicated Westfalia wiring system which has been checked and the caravan lights work independently but when we hitch up the brake warning light comes on.
 we have a Audi A6.  and yes we have cleaned the fittings, and changed the bulbs And checked the earth.  any ideas