In this video, you’ll learn wiring fundamentals for hot rods, drift cars, ratty muscle cars, and race cars. Jeremy from Wiring Rescue covers the wiring of a GM 3-wire 10si/12si alternator, a 12V automotive fuse box, and a starter circuit.
Using 200A Cole Hersee relays, we’ll power the fuse box and the starter. You’ll also discover the differences between continuous and non-continuous use solenoids, and the crucial role of diodes in your wiring setup. This video is your go-to guide for car wiring basics, including race car wiring, alternator wiring, automotive wiring, and more.
How To Wire a Basic Car Circuit: A Step-by-Step Guide
I’m, and today I’m excited to show you how I wired a basic race car circuit. This project includes essential components such as a master shutoff switch, an ignition switch, a neutral safety switch, a GM alternator, a solenoid, a fuse panel, and a starter. In this guide, I’ll walk you through each step to help you understand and replicate the process yourself.
Understanding Solenoids
Let’s start by discussing solenoids. A solenoid is an electrically controlled switch that allows a small circuit to control a larger circuit. There are two types of solenoids: continuous use and non-continuous use. For this project, I used a Cole Hersey 200 amp continuous-use solenoid (part number 24213). This type is suitable for powering up fuse panels and can handle prolonged use. In contrast, a generic Ford starter solenoid is designed for short bursts of electricity and is not meant for continuous use.
Setting Up the Fuse Box
The fuse box is a crucial component in this circuit. I chose a simple fuse box for demonstration purposes. The fuse box needs to be connected to the solenoid, which will control the power distribution. I attached a 194 bulb to the fuse box to visually indicate when the power is on.
Wiring the Solenoid
To wire the solenoid:
- Attach the main battery cable to the left terminal of the solenoid.
- Connect the power output from the solenoid to the positive terminal on the fuse panel.
- Ground the fuse panel using its designated ground section.
- Verify the connections by using jumper wires to activate the solenoid and power the fuse panel, turning on the light bulb.
Adding an Ignition Switch
Next, I integrated a basic ignition switch into the circuit. The ignition switch has four terminals: battery input, accessories, ignition, and start. The setup is as follows:
- Connect the battery input terminal to the power source.
- Link the accessory terminal to the solenoid.
- When the ignition switch is in the accessory or run position, it powers the solenoid, which in turn powers the fuse panel.
Installing a Master Shutoff Switch
A master shutoff switch is essential for safety and compliance with racing regulations. To ensure it functions correctly:
- Wire the master switch to control the power supply to the ignition switch and solenoid.
- Test the setup to ensure that turning off the master switch cuts power to the ignition switch, solenoid, and fuse panel.
Wiring the GM Alternator
I used a GM 3-wire alternator for this project. Here’s how to wire it:
- Connect the main power terminal on the alternator to the battery.
- Attach the voltage sensing wire (pin 2) to the main power terminal.
- Connect pin 1 (dummy light) to the 194 bulb and a diode.
- Ensure proper grounding of the alternator, especially if it’s mounted on a non-metallic surface.
Adding a Diode
A diode acts as a one-way check valve for electricity, ensuring current flows in only one direction. In this setup, it prevents the alternator from back-feeding power through the dummy light circuit when the master switch is off.
Integrating the Starter
The starter in this circuit is wired as follows:
- Connect the large battery cable from the solenoid to the starter.
- Attach a wire from the ignition switch to the starter solenoid.
- Verify the starter functions by turning the ignition switch to the start position.
Including a Neutral Safety or Clutch Switch
For added safety, a neutral safety switch (for automatic transmissions) or a clutch switch (for manual transmissions) ensures the engine starts only when the vehicle is in neutral or the clutch is engaged.
Items Used in this Race Car Circuit:
Video Chapters:
- 00:00 How I wired a basic race car circuit
- 00:50 The difference between continuous and non-continuous use solenoids
- 01:41 What is the purpose of a solenoid?
- 02:08 Overview of the fuse box I use in the video
- 03:08 How to wire a Cole Hersee 24213 solenoid
- 04:12 How to wire the universal ignition switch to the solenoid
- 06:03 How to wire a battery shut-off/disconnect switch to a solenoid
- 07:29 How to wire a GM 3-wire alternator
- 10:06 What is a diode and how does it work?
- 11:58 What happens if I don’t use a diode on my alternator?
- 13:21 Why does a solenoid need a diode across the terminals?
- 13:57 How to wire an automotive starter
- 15:21 How to wire a neutral safety switch or clutch switch in a starter circuit
- 16:39 How to wire a separate starter solenoid to a starter
- 18:53 How to fix a starter that sticks out too long
- 20:00 The importance of fuses and where I would put them
By following these steps, you can wire a basic race or custom car circuit with essential components for safety and functionality. Whether you’re preparing for a race or simply building your vehicle, understanding and implementing these circuits is a valuable skill.