The brake light signal goes through the turn signal cam on cars that don't have a dedicated turn signal (amber) bulb, like the Regals do not. The car has to have a way to interrupt the brake signal, to make it blink. So, you need to check the plugs under the dash, but above the steering column, to make sure they are plugged in and solid, no overheated pins, etc. There will also be a plug in the trunk are, not sure about the exact location, probably drivers side wheel well area. My problem ended up being the turn signal cam it's self. Check the easy stuff first, for sure...need to find a diagram of the turn signal cam and circuit and trace it to see if the signal is making it through the cam and going towards the rear of the car, if not you will need a turn signal cam. As stated above, double check the grounds at the rear of the car, at the light. Keep us posted....