This is a little hard to follow but I would rethink your logic. It sounds like you are co-mingling a switch circuit (brake) and the relay circuit (flasher). There is a reason they are separate. One, is the brake lights should still function if the flashers are activated. I would be trying to find out why there is no power to the relay in the correct configuration. I would expect any connections made from either device to the lights would be parallel and not in series.