ROAMiQ 12V DC Dimmer: wiring guide and FAQ
Wiring for the ROAMiQ 12V DC Dimmer: power, light and wall switch on the 6-position terminal, choosing the Switch Mode, and the built-in overcurrent protection.
What this device does
The ROAMiQ 12V DC Dimmer is a single-channel controller for 12V lighting such as LED pucks, strip lights and cabin lights. It lets you turn a light on and off and set its brightness from the ROAMiQ app, from automations, or from a wall switch. It fades between levels instead of snapping, remembers your last brightness, and measures the light's current so it can shut off if something goes wrong.
Using the screw terminals
Strip about 7 mm (1/4") of insulation. Loosen the screw, insert the bare wire fully into the opening under it, and tighten firmly. Give each wire a light tug to confirm it is held. A loose power or light wire can get hot under load, so do not skip this.
The terminals and where each one goes
The terminal block has six positions. From left to right, as printed on the board:
| # | Label | Connects to |
|---|---|---|
| 1 | GND | Wall switch (either leg) |
| 2 | SW | Wall switch (the other leg) |
| 3 | GND | Battery negative or chassis ground |
| 4 | V+ | Fused +12V from the battery |
| 5 | OUT+ | Light positive (+) |
| 6 | OUT− | Light negative (−) |
Both GND terminals are the same connection inside the dimmer, so it does not matter which one you use for power and which for the switch. The layout above keeps the wires from crossing.
Power
- "V+" goes to a fused +12V source. Your house battery through a fuse block is perfect.
- "GND" goes to battery negative or chassis ground.
Light
- "OUT+" goes to the light's positive (+) wire.
- "OUT−" goes to the light's negative (−) wire.
You can connect several lights to one dimmer by wiring them in parallel: all positives to "OUT+", all negatives to "OUT−". Keep the combined draw under 12A.
Wall switch (optional)
The switch is wired between "SW" and "GND". It does not carry any power; it just connects SW to ground when pressed or switched on. That is why any thin wire (18–22 AWG) is fine here.
Wire one leg of the switch to SW
Connect one terminal of the switch to "SW" (position 2).
Wire the other leg to GND
Connect the other terminal of the switch to "GND" (position 1, or position 3).
Pick the Switch Mode
In the ROAMiQ app, open the dimmer's settings and set Switch Mode to match the switch you installed (see below).
Use a plain, normally-open switch. Illuminated switches that need their own 12V feed are not supported on the SW input.
Choosing the Switch Mode
| Switch Mode | Use it with | What the switch does |
|---|---|---|
| Momentary (default) | Spring-return push button | Tap to turn on or off. Press and hold to dim up or down, then release at the level you want. Double-tap to jump to full brightness. |
| Maintained (position) | Ordinary on/off rocker | Switch on = light on, switch off = light off. The switch position always wins, even after a power blip. |
| Maintained (edge) | Ordinary on/off rocker, when you also control the light from the app | Any flip of the switch toggles the light, whatever position it is in. The switch never fights the app. |
| Detached | Any switch | The switch only reports to the ROAMiQ app and drives nothing directly, so you can use it in automations. |
Hold-to-dim works only with a Momentary switch. With a rocker, adjust brightness from the ROAMiQ app.
Settings you can adjust
All of these have sensible defaults, so most people never touch them:
- Min Brightness (default 5%): the lowest level the light will dim to. Raise it if your light flickers or goes out at the bottom of the range.
- Dim Ramp Time (default 4 s): how long a full sweep takes while holding a momentary switch.
- Power-On State (default Restore): what the light does when power comes back. Restore, Always Off, or Always On.
- Auto-Off Timer (default off): turns the light off automatically after a set number of minutes.
- Double-Tap Full: turns the double-tap-to-full-brightness gesture on or off.
Built-in protection
The dimmer measures the light's current continuously. If the current goes above the Overcurrent Limit (12A by default), for example from a shorted wire or too many lights on one circuit, it shuts the output off and holds it off until you clear the fault. A brief start-up surge when the light first turns on is ignored, so normal LED inrush will not trip it.
To clear a fault, fix the cause first, then tap the wall switch or press Clear Fault in the ROAMiQ app.
The onboard fuse is a last line of defense. A dead short across the light wires can blow it before the electronics react, so double-check your light wiring before powering up.
Troubleshooting
The light won't turn on at all.
Work through these checks in order.
- Check your fuse on the 12V feed first. Replace a blown fuse only with one of the same rating.
- Check power. Confirm "V+" has fused +12V and "GND" goes to battery negative or chassis.
- Check the light wiring. Confirm the light's positive is on "OUT+" and its negative is on "OUT−". Tug each wire to make sure the screw is tight.
- Check for a fault. If the app shows a Hardware Fault or overcurrent, fix the cause, then tap the wall switch or press Clear Fault.
The light is stuck on at full brightness.
The light's negative is reaching ground somewhere other than "OUT−". This is almost always a metal fixture housing bonded to its negative wire and mounted on a metal surface, or a negative wire landed on a chassis ground. Make sure the light's negative connects only to "OUT−".
The wall switch does nothing.
Confirm the switch is wired between "SW" and a "GND" terminal, not to +12V. Then check that Switch Mode in the app matches your switch: Momentary for a push button, Maintained for a rocker. If it is set to Detached, the switch will not control the light directly.
I have to flip my rocker twice after using the app.
Set Switch Mode to Maintained (edge). In that mode any flip toggles the light, so the switch never disagrees with the app.
The light flickers or goes out at low brightness.
Raise Min Brightness in the app until the lowest setting is steady. Some LED fixtures cannot run at very low levels.
The light keeps shutting off by itself.
Check whether Auto-Off Timer is set. If the app shows an overcurrent fault instead, the lights are drawing more than the limit. Reduce the number of lights on the circuit, or check for a damaged wire touching metal.
Still stuck?
We are your installer on call. Reach ROAMiQ support and we will walk you through it.