Multiplex Wiring Systems for RVs: What Are They?

RV wiring has traditionally been installed in a similar manner to electrical wiring in a house. In recent years, however, multiplex wiring systems for RV use have become more common. RV multiplex systems make the wiring throughout the RV more like that of a computer network which can have some real benefits.

But what, exactly, is an RV multiplex system? How does it work? And what are the benefits of multiplex wiring systems for RV use?

In this post, we hope to sort all of that out, so let’s get to it!

How Are Multiplex Wiring Systems for RVs Different from Traditional RV Wiring?

As we noted at the top of the post, RVs have typically been wired in a similar fashion to how a house is generally wired.

How Traditional RV Wiring Works

This means that separate wires are run from the source of power, through fuses or a breaker, to a switch, and then on to a fixture or appliance. With this type of wiring, each switch controls a specific device or string of devices (like several lights or outlets in the same area or on the same wall).

However, changing the configuration of switches/wiring/appliances requires pulling old wires and/or running new ones. This is something that’s particularly challenging in an RV environment.

How Multiplex Wiring Systems for RVs Work

Again, multiplex wiring is more like a computer network which means that power is provided to a common distribution center controlled by signals sent from switch/control panels located throughout the RV.

The switches are often connected to the distribution center using standard CAT5 network wiring or, sometimes, wireless.

In an RV multiplex system, the control panel can be physical buttons, or it can be a digital touchscreen display panel.

With a panel that uses a touch screen, the configuration or controls at any one location can easily be changed. But even on systems using physical buttons, you can re-program them to control something else if desired (though that may require relabeling the button).

The RV industry has made the RV-CAN network protocol standard in recent years. Typically denotes as “RV-C”, this type of network makes it possible for components throughout the RV to communicate with one another.

“CAN” (short for Controlled Area Network) is a technology that’s also used in automobiles and trucks.

What Are the Benefits of Multiplex Wiring Systems for RVs?

Multiplex wiring systems generally offer a number of benefits in RV applications. Among them are the following:

Fewer Circuits Needed

Multiplex wiring reduces the number of circuits needed to wire the RV. This saves weight, reduces the size and complexity of the wiring bundles, and makes installation and maintenance simpler.

Smaller Gauge Wiring

Smaller gauge control wires can be used, which also means lower cost and less weight.

Easy Expandability

Expandability is much easier, so adding functions is possible without a major overall. For example, you could install a multiplex-enabled device with its features and controls available on existing control panels or displays without extensive additional wiring.

Easy Installation

Installation is simple for the RV manufacturer using a standardized harness configuration.

System Intercommunication

Multiplex systems allow increased intercommunication between systems, which enables more centralized monitoring and control.

Increased Automation

The centralized nature of the control in a multiplex wiring system also allows for increased amounts of automation. This can be as simple as the single-push operation of things like light controllers.

For instance, you could set the system to allow you to set lighting “scenes” so you could bring up “Movie Mode”, for example, where powered window shades are lowered and “mood” lighting is set to optimize watching a movie.

Or you could enable voice-activated control for use with hubs like Alexa, Google Nest, or Apple HomePod.

For example, you could say something like, “Alexa, turn on the kitchen lights” or “Alexa, turn on the water pump” (handy if your hands are wet!).

RV manufacturers can also include app-based control systems, allowing you to use your smartphone/tablet to see system settings and statuses, or to control functions like lights, blinds, HVAC, etc., even when you’re not onboard the RV!

Who Makes Multiplex Wiring Systems for RVs?

While there are a number of companies getting involved in multiplex wiring & control systems for the RV industry, the following are some of the most common options:

Dometic Interact System

Dometic Interact, Dometic’s multiplex solution, allows the user to control and monitor all electronic devices throughout the RV with a single touch.

The system allows you to control lighting, your HVAC system, your water heater & water pump, and awnings. You can also monitor the status of your batteries, inverter, holding tanks, and LP gas from several locations in the RV or from the mobile app while you’re away from the RV.

Silverleaf Electronics

Silverleaf’s HMS (House Monitoring Systems) line of products are commonly found in Newmar motorhomes. Various sizes of color touchscreen panels can be used throughout the RV to provide access to lighting, shades, awning, tank monitoring, power and other controls.

Offering comprehensive RV-C support, a Silverleaf multiplex system can integrate with many other onboard systems, including (but not limited to) major brands of inverters, HVAC systems, tank monitors, slide-out controls, awnings, and more.

The interface on the touchscreen panels can be customized for day/night auto-dimming scheduling and/or custom color palettes, allowing the operation experience to be fully customized to match the RV brand and owner’s needs.

In addition to multiplex systems, Silverleaf also manufactures digital dashboards (to replace standard analog gauges) that provide enhanced visibility into vehicle performance and allow for a wide range of custom displays.

Intellitec Road Commander

Intellitec’s programmable multiplex system is known as “Road Commander“. The system offers various modules to control devices and appliances throughout the RV.

Road Commander has an HVAC module that allows control of heating, ventilation, and air conditioning. The system is operated via touchscreens or via Bluetooth on your smartphone or tablet.

If you have more than one HVAC zone, they can either be linked or controlled independently.

The Road Commander Low Current I/O module controls low current loads within the RV, such as interior and exterior lighting.

Road Commander’s High Current Module operates high current loads for such actions as extending/retracting slide-outs or for turning water pumps and water heaters on/off.

There’s also a module for starting and stopping your RV’s generator.

Firefly Integrations (Firefly System & VegaTouch)

The Firefly multiplex wiring system offers switch panels for real-time system monitoring using Vegatouch color touch panels.

These eliminate the need to install a variety of monitors, displays, and switches by combining them into a single switch panel.

The Vegatouch screens allow for the full control and monitoring of an RV’s lighting, HVAC system, awnings, slides, holding tanks, leveling system, water heater & water pump, as well as generator and other customized controls.

Spyder Controls

Spyder Controls designs premium custom electronic control systems for the RV industry and more.

Their multiplex electrical systems are designed for use in the RV, marine, speciality vehicle and heavy equipment industries.

Spyder Controls’ systems use touchscreens and keypad interfaces to sense and control modules, panels, power distribution systems, and other sensor technologies.

Does Your RV Use a Multiplex Wiring System?

If you have experience with multiplex wiring systems in the RV landscape, we’d love to hear from you! Drop us a comment and tell us about your experience!

And if you’re interested in learning more about your RV’s electrical system and wiring, check out our article: RV Wiring For Dummies: Don’t Be Shocked By What You Don’t Know.

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