Customizable Universal Wiring Harnesses for Cars, Trucks, and Custom Builds
Painless customizable wiring harnesses are often referred to as “universal,” but that doesn’t mean complicated. Every harness is designed to be adaptable to a wide range of vehicles while still providing a structured, guided installation. Each wire is clearly labeled every 12 inches, so you always know exactly where it goes and what it does, eliminating the guesswork that typically comes with universal wiring systems. With pre-configured circuits, modern fuse protection, and detailed instructions, these harnesses give you flexibility without sacrificing simplicity.
Customizable Car Wiring Harnesses(Grommet Style)
Classic Customizable wiring harnesses are the go-to solution for traditional builds, routing wiring cleanly through the firewall using a grommet. This setup is ideal for restorations, hot rods, and restomods where simplicity and a clean engine bay layout are key.
Designed to work across a wide range of vehicles, these harnesses provide clearly labeled circuits and an intuitive layout that makes installation straightforward, even for first-time builders. Whether you’re running factory-style components or adding modern upgrades like electric fans, aftermarket gauges, or fuel injection, this system gives you the flexibility to wire it your way without starting from scratch.
Available in both standard and Plus configurations, the Plus versions include a larger fuse block and additional circuits, making them ideal for builds with higher electrical demands or expanded accessory setups.
Basic Universal Wiring Harness
For builders who want a simple, no-nonsense solution, the basic Painless universal wiring harness delivers exactly what you need and nothing more, nothing less. Designed for straightforward projects, this entry-level wiring kit provides essential circuits for ignition, lighting, and charging systems without the complexity of full-feature harnesses. It’s ideal for budget builds, hot rods, rat rods, or minimal electrical setups where simplicity and reliability are key. Even at its most basic level, Painless maintains the same commitment to quality with clearly labeled wires, modern fuse protection, and an easy-to-follow layout that helps you get your vehicle wired and running with confidence.
Classic Customizable Bulkhead Wiring Harnesses
For builders looking for a more sealed, professional-grade firewall pass-through, Classic Customizable Bulkhead wiring harnesses use a bulkhead connector instead of a traditional grommet.
This style is ideal for anyone wanting a more finished and serviceable wiring solution, or reusing the factory bulkhead hole in the firewall. The bulkhead design also makes it easier to disconnect and service wiring when needed, adding long-term convenience to your build.
As with all Painless systems, every wire is labeled every 12 inches, and circuits are laid out in a logical, easy-to-follow format. Standard and Plus options are available, with the Plus versions providing a larger fuse block and additional circuits for more complex builds.
Classic Remote Mount Wiring Harnesses (Trunk Mount)
Classic Remote Mount wiring harnesses are built for vehicles with a trunk-mounted battery or for builders looking to clean up under the dash. By relocating the fuse block and main power distribution, these harnesses help improve weight distribution and create a more streamlined, clutter-free under dash appearance.
Perfect for pro-touring builds, drag cars, and custom applications, this setup allows you to route power efficiently from the rear of the vehicle while maintaining a clean and organized wiring system throughout. Like all Painless customizable harnesses, every wire is labeled every 12 inches, ensuring a smooth installation process from front to back.
Standard and Plus versions are available, with the Plus harnesses offering expanded circuit capacity and a larger fuse block to support high-demand electrical systems and additional accessories.
Customizable Truck Wiring Harnesses
From classic 3100 builds and beyond, Painless customizable truck wiring harnesses are engineered to handle the demands of modern truck restorations and upgrades. These universal truck wiring kits are ideal for projects that combine original style with modern performance, offering support for fuel-injected engines, upgraded lighting, towing accessories, and high-draw electrical systems. Built with durability in mind, each harness features heavy-duty circuits, clear labeling, and simplified installation to reduce guesswork during your build. Whether you’re restoring a vintage pickup or building a custom street truck, Painless truck wiring harnesses give you the flexibility and reliability needed to power every part of your project.
