LED's?

im switching the bulbs in my duster to LEDS, anyone ever done this before? I have the right part number LEDs 1156 and 1157 just like the bulbs were. i took out all the blinker bulbs and the reverse light bulbs and....nothing. When i turn the left blinker on the front left led lights up and stays lit up but doesnt blink and the rear left blinker light doesnt even turn on. Same thing for the other side???

also when i turn the hazard lights on the front two blinkers blink like they should but the rear two dont do anything. whats the deal

i should mention that the blinkers/hazards worked fine before. I also took all the leds out and put the old bulbs in and they work fine again. what am i missing?
Yeah, I went through this too with my '66 Barracuda. When they sell you the $%^& LED bulbs for $10 each, they DON'T tell you that they won't work as a turn signal unless you splice a gizmo for each LED bulb in your wiring. The gizmos cost another $10 or so each. I was hoping to have brake lights that were brighter & not inclined to melt my lenses. Instead I'm $20 poorer & back where I started - hopefully a little wiser, too!