A specialist vehicle conversion can easily add hundreds of switched circuits: warning lighting, work lights, cameras, pumps, tail lifts, environmental controls, payload equipment. Wired the traditional way, each of those is an individual run of cable back to a switch, a relay and a fuse. Multiplexing over CAN replaces most of that with a handful of intelligent modules and a two-wire bus. For anyone building volume or complex conversions, the difference is substantial.
The traditional loom
In a conventional build, every function is point-to-point. A dashboard switch feeds a relay, the relay feeds the load, the load is protected by a fuse, and each of those needs cable of the right gauge running the length of the vehicle. The result is:
- A large, heavy harness with a lot of copper.
- Long build and test times, most of it manual.
- Fuse and relay boards that grow with every added feature.
- Faults that are slow to trace because the logic lives in the wiring.
It works, and for a simple vehicle it is fine. It stops scaling well as soon as the feature count climbs.
What multiplexing changes
A CAN multiplex system splits the job into three parts:
- Inputs: switches, keypads and sensors report to the bus.
- The bus: a two-wire CAN backbone carries messages the length of the vehicle instead of dozens of individual power cables.
- Outputs: intelligent modules near the loads switch power locally, on command from the bus.
The switch no longer carries the load current or defines the behaviour. It sends a message; a programmable module decides what to do and drives the output. The logic lives in software, not in the harness.
What it actually saves
Weight and copper. Power cables run only from a local module to its nearby loads, not from every load back to a central point. Removing long high-current runs and a bank of relays takes real weight out of the vehicle, useful on payload-limited and electric platforms.
Build time. Fewer, shorter cable runs and modular connectors mean faster, more repeatable assembly. A programmed configuration replaces a hand-built relay board, so the tenth vehicle is identical to the first.
Control and flexibility. Because behaviour is programmed, one switch can trigger a sequence (for example, an interlock, a timed output and a warning together) without extra wiring. Changing behaviour is a configuration change, not a rewire.
Diagnostics. The bus knows the state of every input and output. Faults can be reported by the system rather than chased with a multimeter, and load status is available to the operator and to remote diagnostics.
Where Intellitec fits
Intellitec’s switching and control platforms are built for this. iConnex is a CAN switching and control system: a dual-voltage programmable module (ICX-MOD-PRO) at the centre, driven by 3, 4 and 6-way CAN keypads and an OLED DIN switch panel, replacing a conventional relay-and-fuse loom with a small set of intelligent parts. For larger and more complex builds, the PMC Multiplex system scales to a CPU with up to 320 channels, expanded with input, output, relay, solid-state dimmer and I/O modules, while the IPLC range provides rugged programmable control with defined inputs, outputs and voltage monitoring.
When it is worth it
Multiplexing earns its place when:
- The vehicle has many switched circuits or complex interlock logic.
- You build the same conversion repeatedly and want consistency.
- Weight or space is constrained.
- You need diagnostics or remote visibility of the electrical system.
For a handful of simple loads, a traditional loom is still the pragmatic choice. Past that point, the weight, build-time and diagnostic advantages of a CAN system usually pay back quickly. Intellitec’s control hardware is UK manufactured.