How To Make Your Car Remote Start

So, you're thinking about adding remote start to your ride? Excellent choice! Nothing beats hopping into a pre-warmed (or pre-cooled) car, especially on those extreme weather days. This article will guide you through the process, giving you the knowledge to understand how these systems work and, if you're feeling ambitious, even install one yourself. We'll be focusing on aftermarket remote start systems, as factory-installed options vary greatly across manufacturers.

Purpose of Understanding the Remote Start System

Why bother understanding the intricacies? Well, having a solid grasp of your remote start system is crucial for several reasons:

DIY Repairs: When something goes wrong (and eventually, it will), you'll be equipped to diagnose and potentially fix the issue yourself, saving you money and time.
Upgrades and Modifications: Want to add a longer-range antenna or integrate the remote start with your car's security system? Knowing the underlying wiring and communication protocols is essential.
Learning Automotive Electrical Systems: Remote start systems are a great learning platform for understanding more complex automotive electrical principles. You'll gain valuable experience working with relays, wiring harnesses, and vehicle communication buses like CAN (Controller Area Network).
Avoiding Costly Mistakes: A little knowledge can prevent you from making a mistake that could damage your car's electrical system. Understanding the system means you know where not to cut or tap wires!

Key Specs and Main Parts

Before diving into the wiring, let's identify the core components of a typical aftermarket remote start system:

Remote Transmitter (Fob): The handheld device that sends the start/stop signal. Its range is a key spec, often advertised in feet or meters.
Remote Start Module (RSM): The brains of the operation. This is the control unit that receives the signal from the transmitter and orchestrates the starting process. It contains relays and microcontrollers.
Hood Pin Switch: A safety device that prevents the car from starting remotely if the hood is open. This prevents accidental engine starts during maintenance.
Brake Shutoff Switch: Another safety feature. Pressing the brake pedal while the engine is running under remote start will shut it down.
Tachometer Wire/Signal: Some systems require a connection to the tachometer wire to monitor engine RPM. This helps the RSM determine if the engine is running successfully. Newer systems often use data bus communication instead.
Ignition Wires: These wires connect to the car's ignition switch harness and are crucial for mimicking the key-turn process.
Parking Light Wire: Often connected to provide visual confirmation that the remote start has been activated.
Neutral Safety Switch Input (Manual Transmissions Only): A *critical* safety feature for manual transmission vehicles. This ensures the car is in neutral before allowing remote start. Failure to properly install this can result in the car lurching forward when started remotely.

Understanding Remote Start System Wiring Diagrams

The wiring diagram is your roadmap. It tells you exactly how each component connects and what each wire does. Here's a breakdown of common symbols and conventions:

Lines: Represent wires. Thicker lines usually indicate higher current-carrying wires. Dashed lines might represent optional connections or internal module connections.
Colors: Each wire is assigned a color code (e.g., RED, BLU, GRN, YEL). These codes are usually abbreviated. Matching wire colors between the remote start system and your car's wiring harness is crucial for correct installation.
Icons: Represent components like relays (a rectangle with a coil symbol), fuses (a zigzag line), switches (a line connecting to another line), and connectors (a circle or square with pins).
Ground Symbols: Indicate where the system needs to be grounded to the vehicle's chassis. A good ground connection is essential for proper operation.
Voltage Indicators: Show the voltage level of a particular wire (e.g., +12V, GND).
Connectors: Usually depicted as rectangular blocks with numbered pins. The diagram will indicate which wire connects to which pin on each connector.

Example: A line labeled "RED/WHT (Ignition 1)" indicates a red wire with a white stripe that connects to the Ignition 1 circuit in your car.

How It Works: A Simplified Explanation

The remote start system essentially simulates the process of turning the ignition key:

You press the start button on the remote transmitter.
The transmitter sends a coded radio frequency (RF) signal to the RSM.
The RSM verifies the signal and checks the safety interlocks (hood pin, brake switch, neutral safety switch – if applicable).
If all interlocks are satisfied, the RSM activates a series of relays.
These relays energize the car's ignition, accessory, and starter circuits in the correct sequence, just as if you were turning the key.
The RSM monitors the engine RPM (via the tachometer wire or data bus) to ensure the engine has started successfully.
Once the engine is running, the RSM continues to monitor it and shuts it down if any safety interlocks are triggered (e.g., brake pedal pressed).

Newer systems often use a CAN bus interface to communicate with the vehicle's computer. This allows for more sophisticated features, such as door locking/unlocking, alarm integration, and climate control activation, all controlled remotely.

Real-World Use: Basic Troubleshooting

Here are a few common issues and how to address them:

Remote Start Not Working:
- Check the remote's batteries.
- Verify that the hood is closed and the hood pin switch is properly connected.
- Ensure the brake pedal is not being pressed.
- Check the fuses in the remote start module's wiring harness.
- Consult the remote start module's manual for diagnostic codes (often indicated by flashing lights).
Engine Cranks But Doesn't Start:
- Verify that the tachometer wire is properly connected and reading the correct RPM signal.
- Check the fuel pump relay connection.
- Ensure the ignition and starter wires are correctly connected to the car's ignition harness.
Engine Starts and Immediately Shuts Off:
- This can indicate a problem with the anti-theft system. Some vehicles require a bypass module to temporarily disable the anti-theft system during remote start.
- Check the tachometer signal. An erratic or missing signal can cause the engine to shut down.

Safety Considerations

Working with automotive electrical systems can be dangerous if not done properly:

Disconnect the Negative Battery Terminal: Always disconnect the negative battery terminal before working on any electrical wiring. This prevents accidental shorts and potential damage to your car's electronics.
Airbags: Be aware of the location of airbags and avoid working near them. Accidental deployment can cause serious injury.
Fuses: Use the correct size fuse for each circuit. Using a fuse with a higher amperage rating can overload the wiring and cause a fire.
Neutral Safety Switch (Manual Transmissions): This is not just important, it’s paramount. DO NOT SKIP THIS STEP. Verify the neutral safety switch is correctly installed and functioning before using the remote start.
Proper Wiring Techniques: Use proper crimping tools and connectors to ensure secure and reliable wire connections. Avoid using twist-and-tape splices, as they are prone to failure.
Research: Not all vehicles are compatible with aftermarket remote start systems. Some require specific bypass modules or professional installation. Do your research before attempting to install a remote start system.
Professional Help: If you are not comfortable working with automotive electrical systems, it is best to seek professional help. A qualified technician can ensure the remote start system is installed safely and correctly.

Installing a remote start system can be a rewarding project, but it requires careful planning, attention to detail, and a solid understanding of automotive electrical principles. By following these guidelines and consulting the wiring diagram, you can increase your chances of a successful installation.

We have a generic remote start system wiring diagram available for download. While it may not perfectly match every system on the market, it provides a solid foundation for understanding the underlying principles. Please remember to always refer to the specific wiring diagram that comes with your remote start kit for accurate and detailed instructions.

Disclaimer: This information is provided for educational purposes only. I am not responsible for any damage or injury that may occur as a result of attempting to install or repair a remote start system. Always consult with a qualified technician if you are unsure about any aspect of the installation or repair process.