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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