no brake lights when tail lights are on


New Member's Liason
Staff member
BBM Staff Member
Feb 3, 2013
Overbrook, Ok, USA
ok i used to be a whiz a trailer lights but im running out of ideas. the brake lights and turn signals work when the tail lights are off but when they are on and the brakes are applied it all goes dark on the trailer. if anyone has any suggestions of what i need to check next i would appreciate it