Whelen PLF46 Programmable Universal Flasher
Whelen PLF46 Flasher
The Whelen PLF46 is a compact, fully programmable solid-state flasher for warning lights on emergency, commercial, and utility vehicles. It sits between a simple flasher and a full lighting controller: six independently assignable outputs, four programmable inputs, and configuration through Whelen Command over USB-C.
CORE SPECS
- Voltage: 10–30 VDC
- Outputs: 6 positive-switching channels, 6 A each, 36 A total
- Inputs: 4 programmable inputs + ground
- Sleep current:~200 µA when no outputs are active
- Temperature: −40 °C to +60 °C
- Rating: IP67 with the USB-C cap fitted
- Connectors: right-angle waterproof plugs (outputs, power, inputs)
- Size: roughly 4.7" × 4.25" × 2.56" (compact vs older SmartLogic flashers)
Each output is internally fused at 6 A. Do not fit larger fuses. Typical power per outlet is about 77 W at 12.8 V.
WHAT IT CAN DO
Programming (via Whelen Command)
- Connect a USB-C cable (not included) and use Whelen Command to:
Assign any flash pattern to any output
Group or independently control the six outputs
Map the four inputs to patterns, phases, low-power, or custom logic - Enable DVI™ (Dynamic Variable Intensity — smoother night dimming / intensity change)
Enable Steady-Lock® (hold a steady burn instead of flashing when required)
Set low-power / cruise behaviour - It ships with a default map so it works out of the box:
- Input 1 → outputs 1 & 2, SignalAlert 75 phase 1
- Input 2 → outputs 3 & 4, SignalAlert 75 phase 2
- Input 3 → low power on outputs 1–6
- Input 4 → unused by default
All of that can be rewritten in software. Retailers typically list 62 Scan-Lock patterns, plus alternating, simultaneous, and synchronized modes.
Protection and diagnostics
Short-circuit and overcurrent protection per output
Thermal protection
Status LED: solid green = active, blue = USB traffic, flashing green/yellow = fault / overcurrent
Compatibility
Works with Whelen LED / Super-LED lightheads and many halogen heads. It is specifically called out as compatible with newer products such as VXE warning lights. Lights are wired as positive-switched; the lamp negative goes to chassis ground.
Typical Uses
Driving multiple lightheads or small modules (grille, dash, deck, surface-mount LEDs) without adding a full WeCan / Core system. Useful when you need more current and more programmable channels than a basic 2- or 4-outlet flasher, but do not need a networked controller.
Practical limits: 6 A per channel is plenty for most modern LED modules, but not for large halogen bars or many high-draw heads on one output. Keep total load within 36 A and size supply wiring accordingly (the install sheet includes a wire-gauge chart). Leave the USB-C cap on for the IP67 seal.
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