When i hit the brakes on my 66,the right one works but not the left,but both the signals work,the running lights work(until i hit the brakes)then the whole light on the left won't work.I checked the circuit from the back to under the dash and there is no power when the brakes are applied,but the turns work on the same circuit and it has power then.Changed the bulb numerous times.Could it be the brake switch?Or maybe someone here can point me in the right direction...Thanks.