7-Way Truck-Side to 4-Flat Trailer Adapter with Built-In LED Tester
Part Number: F7KL
Truck-side 7-way blade to 4-flat trailer adapter with integrated LED circuit tester. Designed to quickly verify truck-side trailer lighting functions before troubleshooting the trailer.
The built-in LEDs instantly show whether the tow vehicle is supplying power to each circuit, eliminating guesswork caused by blown trailer-specific fuses common on late-model trucks.
Features
- Truck-side 7-way blade to 4-flat trailer adapter
- Integrated LED tester confirms truck output circuits
- Molded ABS black housing with clamshell design
- Quick plug-in installation
- Includes additional auxiliary wires if needed
- Durable wire insulation and strain relief
Additional Wires Included
- White — Ground
- Black — 12V Auxiliary Power
- Blue — Electric Brake Output
- Large Yellow — Backup / Auxiliary Circuit
Wire Gauge Specifications
- 14 gauge — Red, Brown, Green, Yellow
- 12 gauge — Blue
- 10 gauge — White and Black
Wiring Reference Table
| Molded Connector Wire | Function | Typical Trailer Wire |
|---|---|---|
| White | Ground | White |
| Red | Left Turn / Brake | Yellow |
| Brown | Right Turn / Brake | Green |
| Green | Tail / Marker Lights | Brown |
| Blue | Electric Brake Power | Blue |
| Black | 12V Hot Lead | Black |
| Yellow | Auxiliary | — |
Installation Notes
- LED indicators confirm truck-side output only
- Trailer wiring should still be verified independently
- Do not rely solely on wire color — always test circuits