Who knows about turn signal wiring?

Ok, this is on my 56 Dodge truck, FYI, there is no stock wiring I have completely re-wired it from scratch. EVERYTHING works, gauges, lights etc. Here is my issue, the round tail lights for the utiline box which have LED 1157 equivalent bulbs work when you step on the brakes and when you operate the signals, BUT when you step on the brake when either signal is on then the brake over rides the signal and only the brake lights stay on. Note: my brake light function dosnt go through the steering column as it would on a a body or most cars. The signals do. The steering column is a Chrysler telescoping and tilting column probably from a mid seventies imperial or like car, can't say for sure. The brake switch is a universal Amazon adjustable brake switch which adjusted nicely to fit the pedal. The left signal and right signal are connected in line with the brake light and I used two diodes near the tail lights to keep the signal from back feeding to the brakes. So.....short of adding separate amber lights to the rear circuit which I have contemplated is there any way of making them operate properly?