In the high-dollar sport of auto racing where an engine can cost as much as or more than the average family home, the task of monitoring engine function is very important. It is no wonder then that the job of wiring the switch panel is one of the car builder's most important tasks. What may be a surprise to many people is that the equipment utilized in the switch panel is not the most expensive that money can buy. It is, however, important that it is assembled correctly and with attention to detail.
Park the car on a well-lighted, flat and level surface. Remove the battery's positive cable with a wrench.
Decide on a mounting location for the switch panel. Keep in mind that this panel will need to be mounted in a location where a belted-in driver can reach it with ease. Also check the rulebook for your track, as they often have mandated locations for battery and fuel kill switches.
Create a diagram. Decide how many circuits you will need. For the most basic switch panel you will need a main power on/off switch, ignition and a push-start button. Using a pen and paper, draw the wiring diagram to show how you will lay out the switch panel. In the diagram, refer to the wire size and switch amperage rating. This will aid in replacement should the need arise.
Wire the panel. Connect the positive side of the kill switch to the positive cable on the starter and the negative side of the kill switch to the engine block. Use only TXL or SXL wire (found in high-end electrical supply houses), which has a higher heat rating than wire you will find in discount parts stores. Cut the wire with a wire cutter and strip it back about 1/4 inch with stripping pliers. This will prevent cut and frayed wire strands from stripping the wire with a knife. Crimp the terminal ends to the wire with a wire crimper.
Solder the crimped connections with a soldering iron and place heat shrink tubing over the connection. Heat the tubing with a heat gun to shrink it around the soldered connection. This will prevent vibration from weakening the connection.
Screw one end of the wire's terminal to the fuse block with a screwdriver. Place a drop of liquid tape over the screw to prevent it from backing out due to vibration. Place the other end of the wire to the starter cable bolt. Tighten the bolt with a wrench and place a drop of liquid tape over the bolt. Wire the ignition switch in the same manner by connecting the switch to the positive side of the coil. The starter button will be wired in the same manner from the button (switch) to the starter solenoid. Take your time and solder and heat shrink all connections. Continue this manner of wiring for all of the switches you have incorporated into your panel.
Secure the harness. Use plastic zip ties to secure your new wiring harness. Take special care to route the wires away from heat sources and sharp edges that might fray the wires. Often, an old piece of vacuum tubing can be cut and placed around your new wiring harness to protect it from abrasions. Split the tubing with a razor knife, place the wiring harness inside of the tubing and secure it with zip ties.
Mount the panel. Once you have the panel wired, you can mount the panel by inserting a drill bit into the drill motor and drilling through the panel and into the race car's roll bar. Insert a pop rivet into the rivet gun and place it into the drilled hole. Squeeze the rivet gun until the rivet pops. Repeat this process of drilling and riveting around the perimeter of the switch panel until it is mounted securely to the roll bar.