1. Introduction
This manual provides comprehensive instructions for the installation, operation, and maintenance of your Partsam 17 Inch 40 LED Red Trailer Light Bar. Designed for heavy-duty trucks, semi-trailers, cargo trailers, boat trailers, work vehicles, and other overland vehicles, this light bar offers reliable and DOT compliant lighting. Please read this manual thoroughly before installation and use to ensure proper function and safety.

Image 1.1: The Partsam 17 Inch 40 LED Red Trailer Light Bar, showcasing its bright red LEDs and chrome bezel.
2. Product Features
- LED Count: Equipped with 40 super bright NICHIA Super FLUX LEDs for high visibility.
- Functions: Operates as clearance, side marker, identification light, stop light, turn signal, and tail light.
- Construction: Completely sealed and waterproof (IP67 rated) for durability in various weather conditions.
- Lens Material: Features a polycarbonate lens that is sonic welded to the housing for enhanced protection.
- Compliance: SAE Approved and DOT Compliant, meeting safety standards.
- Voltage: Designed for 12V electrical systems.
- Mounting: Surface mount design with two screw holes for secure attachment.

Image 2.1: A detailed view of the 40 super bright LEDs and the chrome bezel, highlighting the light bar's robust design.

Image 2.2: Illustration emphasizing the polycarbonate sturdy lens, vacuum-sealed construction, and DOT compliance of the light bar.
3. Package Contents
Verify that all items are present and undamaged upon opening the package.
- 1 x Partsam 17 Inch 40 LED Red Trailer Light Bar
- Mounting Screws (pre-installed or included separately)
4. Safety Information
Always observe the following safety precautions during installation and operation:
- Disconnect the vehicle's battery before performing any electrical work to prevent electrical shock or short circuits.
- Ensure all wiring connections are secure and properly insulated to prevent corrosion and electrical issues.
- Do not exceed the specified voltage (12V) for this light bar.
- Mount the light bar securely to prevent it from detaching during vehicle operation.
- Consult a qualified technician if you are unsure about any part of the installation process.
5. Setup and Installation
5.1. Dimensions
Before installation, confirm the dimensions of the light bar to ensure it fits your intended mounting location.

Image 5.1: Diagram showing the length (approximately 17.12 inches) and height (approximately 0.83 inches) of the light bar.
5.2. Wiring Instructions
The light bar features a 3-wire connection system. Proper wiring is crucial for correct functionality.
- White Wire: Connect to the vehicle's Ground (Negative).
- Red Wire: Connect for High Brightness, typically used for the brake/stop light function.
- Gray Wire: Connect for Low Brightness, typically used for the tail/running light function.

Image 5.2: Visual guide illustrating the three-wire connection: White for Ground, Red for High Brightness (Brake/Stop), and Gray for Mid Brightness (Tail/Running).
5.3. Mounting
The light bar is designed for surface mounting. It includes two screw holes for secure attachment to a flat surface on your vehicle or trailer. Ensure the mounting surface is clean and flat before installation.
- Position the light bar in the desired location.
- Mark the positions for the two screw holes.
- Drill pilot holes if necessary, ensuring they are appropriate for the provided screws.
- Secure the light bar using the provided screws, ensuring a snug fit without overtightening.
6. Operation
Once properly installed and wired, the light bar will function according to the electrical signals from your vehicle:
- When the vehicle's running lights are on, the light bar will illuminate at low brightness (via the Gray wire).
- When the brake pedal is pressed or a turn signal is activated, the light bar will illuminate at high brightness (via the Red wire).
This dual-brightness functionality allows it to serve as a tail light, stop light, turn signal, and identification light.
7. Maintenance
The Partsam 17 Inch 40 LED Red Trailer Light Bar is designed for minimal maintenance due to its sealed, waterproof construction and LED technology.
- Cleaning: Periodically clean the lens with a soft cloth and mild soap and water to remove dirt and debris that may obstruct light output. Avoid abrasive cleaners.
- Inspection: Regularly check the mounting screws for tightness and inspect the wiring for any signs of wear, corrosion, or damage.
- Waterproof Integrity: The light bar is IP67 rated, meaning it is protected against dust and can withstand immersion in water up to 1 meter for 30 minutes. Avoid prolonged submersion or high-pressure water jets directly on the seals.

Image 7.1: Illustration highlighting the IP65 waterproof rating, indicating the light bar's durable polycarbonate lens and housing.
8. Troubleshooting
If you encounter issues with your light bar, consider the following:
- Light Not Illuminating:
- Check all wire connections (ground, power) for looseness or corrosion.
- Verify that the vehicle's electrical system is providing 12V power to the light bar wires.
- Inspect the vehicle's fuses related to the lighting circuit.
- Incorrect Brightness/Function:
- Ensure the Red and Gray wires are connected to the correct high and low brightness circuits, respectively.
- Confirm that the vehicle's signals (brake, tail) are functioning correctly.
- Flickering Light:
- Check for loose connections or intermittent power supply.
- Ensure proper grounding.
If problems persist after checking these points, contact Partsam customer support for further assistance.
9. Specifications
| Feature | Specification |
|---|---|
| Brand | Partsam |
| Model Number | 187235 |
| LED Count | 40 LEDs |
| Color | Red |
| Voltage | 12V |
| Wattage | 40 watts (estimated, based on product description) |
| Waterproof Rating | IP67 |
| Lens Material | Polycarbonate |
| Compliance | SAE Approved, DOT Compliant |
| Item Weight | 1 pound |
| Package Dimensions | 17.72 x 3.5 x 1.22 inches |
10. Warranty and Support
For warranty information or technical support, please refer to the official Partsam website or contact their customer service directly. Keep your purchase receipt as proof of purchase.
Partsam Customer Service: Please visit the Partsam Store on Amazon for contact information or product support resources.