When I bought my 70 cuda it came with the 3-speed switch instead of the variable switch and would only run on fast and not park correct as Kim stated. I looked and the two wire plug (red & green) wasn't hooked up. The minute I put it on the switch it started smoking. I talked to Jim at JS restorations and he said you need the variable switch to work correct and those wires with that switch causes a dead short. There are a couple of the correct 70-71 switches on e-bay. Good luck, Mike