Parking brake problems

My parking brake isnt much to write home about. It can brake the car, but it wont lock and the vacuum release switch is not working or is maladjusted.
But I cant figure out if there is a switch for the brake light in the instrument panel. I cant find one thats connected to the parking brake. According to the owners manual, the light would go on if the paring brake is applied when the key is on. The bulb works, it lights when the starter turns.
Imperial 1969.