FYI - on the '67's there are TWO separate flasher modules required to complete all the circuits. There is one on the fuse panel for the turn signals and there is a 2nd one at the end of a wire lead all by itself. The 2nd allows the emergency flashers to operate. I found this out the hard way.
I don't remember if the emergency flasher module affects the brake lights, but check it out. That flasher does light up the same elements on the tail light bulbs as the brake pedal.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI