I have a '79 Chevrolet K-20. The taillights/parklights (not brake light) will not go off. I took out the light switch and unplugged the lights-they stayed on. I pulled every fuse in fuse block one at a time and they never went off. I unplugged the rear light wiring harness and the back lights went off but the park lights stayed on. I am out of ideas and would appreciate any help. Thanks