You may have seperate brake and turn light circuits. If so you will need a converter put in line to mix the circuit for the toad. A 3 to 2 converter should do the trick.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7