drfeelgood

hi everybody
Got a small question about this brake light that keeps coming on and i hear a noise from the front drivers side like a compressor stuck on , i,ve unplug a connection where the noise is coming from ,cleaned it out and than pluged it back in and this did stop the the compressor and light from coming on until a couple of days ago when i did this unpluging and cleaning bit ,but can,t get the compressor to stop , any ideas as to what the problem is and if it knacked what part am i looking for and how easy is it to fix and change , any help is appreciated , thanks