American Autowire 510825 Highway 15 Plus Universal Wiring Harness

The Highway 15 Universal Wiring System has been the perfect choice for tight spots in kit cars, roadsters and coupes. Since its introduction in 2003, American Autowire listened carefully to the customers to see how they could improve their original design.

American Autowire is exceptionally grateful to be part of so many builds, and have taken note of some suggestions from over the years to make a great product even better. With those thoughts in mind, American Autowire is pleased to introduce the Highway 15 Plus!

The goal with the changes in the Highway 15 Plus is to preserve the same feel as the original, with some modernization and ease-of-use improvements for both backyard and professional builders. New features include:

• A built-in LED flasher to support LED turn signals without the need to purchase an additional item.
• A back up light feed and power wires to make the harness easier to install in a more modern vehicle.
• Improvements to our instructions to cite a wider range of examples and real-world scenarios. The panel labeling has also been updated along with the above physical changes, including wording modifications for enhanced clarity.
• Our new high amp alternator and main power connection kit. This allows for the use of high amp alternators, and provides an even better level of fuse protection for the panel and charging system. This new connection kit utilizes 6ga wire and two 175amp Megafuses.
• Extra connectors and wiring to more easily support a 4-headlight system without an additional add-on purchase.
• Longer neutral safety wires for cars with console shifters.
• An additional ignition circuit to support aftermarket components.
• Improved ignition switch with mating connector and 4 additional accessory and ignition terminals. Uses a square GM-style key.

These original features that made the Highway Series the most popular wiring system available are still part of the new Highway 15 Plus:

• G-10 composite panel base measuring 4.5”L x 4.5”W x 3.5”H, and nylon 6/6 panel components.
• GXL/XLPE GM color-coded wire.
• Easy-to-read wire labeling every 3”-4”.
• Self-locking screw clamp interface.
• American Autowire’s signature gauge cluster disconnect.
• Ignition, headlight and dimmer switches are included.
• Full-color, tabloid-sized, step-by-step instructions.

Instruction Sheet for Highway 15 Plus (PDF)

Warning & Contents Sheet (PDF)

Alternator Connection Kit (PDF)

Ignition Switch & Starter Connection Kit (PDF)

Highway 15 Plus Series Panel (PDF)

Headlight Switch Connection Kit (PDF)

Steering Column & Turn Signal Connection Kit (PDF)

Gauge Connection Kit (PDF)

Accessory Wire Connection Kit (PDF)