mean green cobra

I recently ran into a problem with my brake light and turn signal. the light come on as they should. the right side turn signal and brake light work fine. but the left side brake light and turn signal aint working . when u put the turn signal to the left it makes a weird noise from the relay under the dash. does that mean the relay is bad . could it of went bad on just the left side lights and not the right side. when I put a test light on 2 different plugs it makes that weird noise . thanks for your help