Can anyone tell me what colour wires are on the ballast resistor for the coil on a 71 1200 sedan I have one with a black and white with a red and blue connected together and the other is just a black and white wire . When you turn the ignition on they both have power I thought there would only power in one as it went threw the resistor to the coil. I have found this is why my tacho isn't working .any suggestions