Electrical problem?

Car won’t go into drive unless the lights and radio are shut off. I’ve had the range transmission switch replaced twice and when driving the gear indicator says the car is in reverse, when brakes are depressed it indicates the car is in drive. Also the blinkers occassionally do not work or won’t work if the brake pedal is depressed. They either flash quickly or not at all. Is this an electrical issue?

Check and clean all body ground points