Relay for Turn Signal/Brake Priority

Im am dealing with a similar issue. I found this thread on a google search. (Already a memeber though...) I have an 88 Suzuki Samurai that had aftermarket tail lights done when I got it. Trailer type lights, 4" round tail/brake lamps, and 2" turn signals. Since I had no reverse lights (and no room left in the tailgate!) I decided to replace the turn signals with clear lamps and run reverse lights to them and use a _TRAILER TAIL LAMP CONVERTER_ It worked great, turn signals flashed with the brake light. Then I turned on the headlights... with the headlights on it wont flash. whats more is the hazards will flash with the headlamps on but only in the front. Everything is wired correctly. Im thinking the flasher module has the incorrect load. Before I did this rewire the turn signals flashed fast, as the front turn signals were smaller than stock(even with the side markers wired into them). I considered the possiblity of a "heavy duty" flasher module. any input is appreciated.