It has been a while since I have been on here. I have a 1959 Chevrolet fleetside apache 3 speed 235 engine. The taillights suddenly quit working. I have checked the bulbs and wiring and they are good. I can put twelve volts to the tailight wires and they come on. When I turn the lights on with the switch on the dash the headlights come on but not the taillights. With the switch off at the dash the blinkers on the head and tailights work but when I turn on the head and tailights by the switch on the dash the blinkers quit working. The headlights will stay on but no tailights. Any ideas on what to check would be helpful. Is it possible that the switch is bad? Thanks for any help.