tail lights wired into blinkers

Oh you're in for a treat! You'll have to do what I did with my old '85 Scottsdale. Buy a needle test light. Turn on the blinker. Make sure you hear the click, click noise under the dash. If you don't all you may need is a new blinker relay. If you do hear the clicking, take your needle and start probing the wires under the hood. The light should blink on your tester when you've found the right wire. Then just start tracing the wires. You'll probably find a broken wire or bad grounds. Or you may have to rewire half of the vehicle like I had to. Good luck!