Off-road vehicle enthusiasts and DIY mechanics often seek tools that enhance their experience on rugged terrain and simplify post-trip maintenance. One such essential accessory is the ARB on-board air compressor. These units not only power ARB Air Lockers but also allow users to adjust tire pressure with ease—whether inflating for a drive on the highway or deflating for improved off-road traction.
This guide draws from verified installation instructions and technical insights provided in multiple sources, including official documentation and detailed user reports from U.S.-based installers. It outlines the key steps, tools, and considerations for installing an ARB twin compressor in a vehicle, focusing on wiring, mounting, and accessory integration. The goal is to provide a clear, actionable resource for anyone planning to install an ARB air compressor in their off-road rig.
Understanding ARB Compressor Models and Requirements
ARB compressors are available in several models, including the high-output CKMA12 and the twin compressor units. Each model comes with a full wiring harness, mounting hardware, and a pressure limit switch, but the installation specifics vary slightly depending on the model and the vehicle.
A critical requirement for most installations is the use of an ARB Compressor Manifold or a remote coupling setup, especially when the compressor will be used for tire inflation. Direct attachment of a hose coupling to the compressor is not recommended in this case. The manifold ensures that air is distributed properly to accessories like air lockers and tire valves.
For users not utilizing air lockers, it is possible to bypass the manifold setup by using a remote coupling. This method involves a combination of fittings, hoses, and adapters, which must be sealed properly with thread sealant to prevent leaks. Users should also be aware of the recommended mounting distances—no more than 9 inches between the compressor and the manifold.
Preparing for Installation: Tools and Parts
Before beginning the installation, it is essential to gather the appropriate tools and parts. The following items are commonly used across multiple installation reports:
- Basic mechanics toolset: This includes wrenches, screwdrivers, pliers, and a socket set.
- Wire cutters, strippers, and crimpers: Essential for preparing and connecting wires.
- Multimeter: Used to test electrical connections and verify proper functionality.
- Heat gun and heat shrink: For insulating wire connections.
- Thread sealant: Necessary for sealing threaded fittings.
- Electrical tape or heat shrink: For insulating and securing connections.
- Cable ties and wiring loom: For organizing and bundling wires.
Additional components such as ring terminals (8-gauge and 6-gauge AWG), alligator clips, and specialized brackets may also be required, depending on the compressor model and the vehicle’s mounting capabilities. Some users opt for third-party brackets, such as the M.O.R.E. ARB Twin Bracket, which can simplify the installation process by providing a pre-designed mounting solution.
Mounting the ARB Compressor: Step-by-Step Process
The mounting process begins with identifying a suitable location for the compressor. While ARB compressors come with a built-in mounting bracket, some users prefer to use vehicle-specific brackets for easier installation and better accessibility.
If using the built-in bracket, the process involves marking and drilling holes in the desired mounting location, then securing the compressor with the provided hardware. For third-party brackets, the compressor is first attached to the bracket before securing the bracket to the vehicle, following the manufacturer’s instructions.
One installer detailed the challenges of finding space in a compact engine bay, such as that of the Ram 3500. In this case, the compressor was mounted behind the driver-side headlight after removing several components, including the windshield washer reservoir and a large air hose, to create sufficient clearance.
Regardless of the mounting location, it is important to ensure the compressor is securely fastened and positioned away from heat sources or moving parts that could interfere with its operation. Users should also consider routing the air hose and electrical wiring in a way that minimizes the risk of damage from vibration or exposure.
Wiring the ARB Compressor: Electrical Connections and Safety
Wiring the ARB compressor involves connecting the power and ground wires to the vehicle’s electrical system. This process is typically straightforward, but users must take care to ensure proper insulation and secure connections to prevent short circuits or electrical failures.
The power wire is connected to the battery, while the ground wire is connected to a suitable grounding point, often a metal part of the vehicle’s chassis. Both wires are stripped, twisted together, and crimped using a 6 AWG ring terminal. A piece of heat shrink is applied over the crimped connection to provide additional insulation and protection.
For users with switch panels like the sPOD or Switch-Pros, a quick-connect harness can be used to simplify the wiring process. This allows the compressor switch to be integrated with other vehicle controls without the need for custom wiring. However, for those without a switch panel, an alternative wiring method must be used, which typically involves running the wires from the battery to the compressor and securing them along the firewall or another suitable route.
Before finalizing the installation, it is recommended to test the wiring harness and compressor operation. This can be done by temporarily connecting the power and ground wires and observing whether the compressor starts and runs as expected. If any issues arise, such as a failure to power on or unusual noises, the wiring should be inspected for loose connections or incorrect polarity.
Installing the ARB Compressor Manifold or Remote Coupling
As previously mentioned, the ARB Compressor Manifold is required for both air locker operation and tire inflation. If the user does not plan to use air lockers, a remote coupling setup is an alternative option.
To install the manifold, thread sealant is applied to the ¼” fittings, which are then connected to the compressor and the manifold using a 14mm socket. The hose coupling is threaded into the large port on the manifold, and the stainless-steel braided air hose is connected using a 14mm wrench. The manifold should be mounted within 9 inches of the compressor for optimal performance.
For a remote coupling setup, users will need to assemble a combination of fittings, hoses, and adapters. This typically includes a hose coupling, coupling dust cap, reinforced hose, and JIC adapters. Thread sealant is applied to all fittings, and the JIC-4 fittings are assembled without the need for additional sealant due to their flared design.
Once the remote coupling is assembled, the hose is connected to the compressor using a 14mm socket, and the 90-degree fittings are used to prevent kinks in the reinforced hose. The coupling should be mounted in a location that is easily accessible for tire inflation but protected from dirt and debris.
Finalizing the Installation: Routing Wires and Securing Components
After the compressor, manifold, and wiring have been installed, the final step involves routing the wires and securing all components in place. This is a critical step to ensure the longevity of the installation and to prevent damage from vibration or movement.
Wires should be routed along the firewall or another protected path to avoid exposure to heat, moisture, or mechanical stress. Cable ties and wiring loom are used to bundle and secure the wires, preventing them from rubbing against other components or becoming entangled.
Extra wiring loom can be used to secure the harness underneath or behind the mounting bracket, ensuring that all connections remain in place and are not subjected to unnecessary strain. Once the wiring is in place, the power and switch wires are connected to the compressor, and the unit is prepared for final installation on the bracket.
Some installers find it helpful to pull back the engine weather stripping to gain better access to the compressor during this stage. Once the compressor is mounted and the wires are secured, the unit is ready for testing and use.
Testing and Troubleshooting the ARB Compressor
Before using the ARB compressor in the field, it is essential to test its operation. This can be done by connecting the power and ground wires and observing whether the compressor starts and runs smoothly. If the compressor fails to start or exhibits unusual behavior, such as excessive noise or vibration, the wiring and connections should be inspected for issues.
Common troubleshooting steps include checking for loose or damaged connections, verifying that the pressure limit switch is functioning correctly, and ensuring that the air hose and fittings are properly sealed and connected. If the compressor does not reach the expected pressure level, the air filter or pressure sensor may need to be inspected for clogs or malfunctions.
If the user has installed a remote coupling setup, it is important to verify that the hose is not kinked or restricted and that the coupling is securely connected to the compressor. A leak test can also be performed by applying soapy water to the connections and looking for bubbles, which would indicate a leak.
Conclusion
Installing an ARB on-board air compressor is a valuable addition to any off-road vehicle, providing the convenience of tire pressure adjustments and the ability to power air lockers. With the right tools, parts, and installation instructions, the process can be completed in a few hours, even for those with limited mechanical experience.
Key considerations include selecting the appropriate mounting location, ensuring proper electrical connections, and using the correct accessories such as manifolds or remote couplings. By following the steps outlined in this guide and referring to the manufacturer’s documentation, users can successfully install their ARB compressor and enjoy the benefits it provides on and off the trail.