What signals do you have in the back? I had a weird problem with mine too. I have the Track-77s up front and the Track-11s in the back. When I installed the 77s up front I just used the load boxes and they tested fine. When I hooked up the 11s in the back with just the load boxes both the fronts would blink fast then get dim, the rears would just get dim.
When I hooked up the stock rear signals everything was fine again. The instructions really didn't help so I just tried to hook up the 11s with the load boxes AND the resistors. That did the trick.
So for my setup on an '06 S2R, I used just the load boxes up front
and load boxes with 2 resistors for the rear. I thought I read somewhere that if you hook up the LED lights without the load box, that can fry them.
Hope that helps...