Trailer brake issues

[James McClure]

Morning everyone. Problem, trailer brakes pulsate (apply then release) when 4 way flashers operating. Brakes, electronic brake controller and all lights function as they are designed. I know what the cause is (4 way flashers use the brake light circut, not the signal light circuts) I thought of several different ways to beat this, but all of them are rather cumbersom or draw to much current. I thought of using a switch to stop the backfeed into the controller to kill brake imput, but then I wouldn't have trailer brakes when the 4 ways were on. I thought of using a relay but the added load of the relay coil would strain an already loaded circut. My last idea was to use a diode to stop the backfeed into the brake light circut and still have the trailer brakes operate normally. Diode has to be able to handle at least 10 amps, 15 or 20 would be better. Question, does anyone know where I might locate such a diode? Radio Shack isn't any help and the trailer place doesen't even understand the problem. Many thanks, Jim