Vehicle will not shift out of the park poisition while the van is running.

The van will not shift out of park while the van is running. Also the brake lights are not working. However, if you put the van in nuetral and start it then the vehicle can be shifted into reverse and drive, but the brakelights still wont work. I have replaced the switch at the brake pedal and this did not fix the problem. I heard it may be a cable or a relay. Could you please advise? Thank you