Expert: Brad Sears - 3/6/2011

Question
My sons 51 chieftain was a victim of an ignition switch bypass and we are trying to figure out which wires go to the new switch. The engine will crank with the push button and the low beams work. No dash lights or working gauges. We found the back of an old ignition switch with two hot wires (for the gauges) and a ground run to one terminal. The other two had no wires running to them. Any thoughts?

Answer
This car uses a three terminal ignition switch. One terminal is the hot or battery wire and is connected to the output side of the ammeter. The second terminal is the ignition terminal and runs directly to the + side of the ignition coil. The third terminal is the accessory terminal and runs the gauges, radio, heater, back up lamps, and directional. Most of the original wiring in the car should be cloth covered and a neutral color. The wires are identified by a cross tracer woven into the fabric. Some tracers are diagonal and others are cross or perpendicular to the wire. The color codes for the wires running to the ignition switch are:
Battery wire, red tracer. That is a diagonal tracer.
Ignition to coil, black.
Accessory. According to my wiring diagram there are three wires that connect to the Acc terminal. One has black cross tracers and two have red cross tracers.