If using the 2 prong flasher is preferred then the idea of diodes would work fine. That is the way the add on 3rd brake light works if you don't want to run a wire all the way up to the brake light or turn switch.
George
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne Super In the Gallery Forum