Painless Wiring Kit - How to Harness Your Electrical System

Ah, what a joy it is to transform a pile of parts into a fire-breathing custom car. Right? But one aspect most of us dread is wiring, usually considered the auto equivalent of the root canal. Even performance enthusiasts, who are comfortable handling complex mechanical tasks, blanch when faced with a spool of 10-gauge wire and a schematic diagram.

But times have changed. Such fear is misplaced in light of the kit car industry's ever-advancing aftermarket. Now any enthusiast, no matter how electron-challenged, can wire a car into a reliable, safe runner. The chore of stringing wires has been simplified by the emergence of the wiring kit, perfected by Painless Wiring of Ft. Worth, Texas.

To show just how easy it is to wire a kit car, we visited Lone Star Classics, which offers a Cobra replica among its line of kits. Every Lone Star Cobra, whether sold in kit form or as a turnkey vehicle, uses Painless Wiring's basic 12-circuit wiring harness.

The beauty of a Painless kit is that all wires are preconnected to the fuse panel, making installation a three-step process. First, mount the fuse panel in a convenient location, usually under the dash. Next, route the wire groups, or sections--headlight section, taillight section, engine section, etc.--where they need to go. Finally, connect the wires, lights, switches, gauges, and so on.

Painless kits use standard GM color coding, but the Painless instruction booklet describes hookup of all makes of steering columns and ignitions. Along with the fuse panel and wires, the kit comes with steering column connectors, headlight plugs, tie wraps, an ample supply of crimp and solder connectors, and instructions. The instruction booklet identifies each wire's color, destination, and origin. Also, complete wiring diagrams are included.

Before you head to the garage, here are a few basic pointers to help with a successful wiring job.

Ground Attack

For an electrical system to work properly--particularly on fiberglass cars--it must be well grounded. Dennis Overholser, tech guru at Painless Wiring, says you must run a ground strap from the engine/trans to the frame. Interior and gauge wiring must also be grounded to the frame. For a solid connection, scrape off paint so the ground makes a good contact. Star washers, with their pointy little teeth, help too.

Tie One On

When routing wires, use nylon ties every 2 to 4 inches to make neat bundles. Lone Star encases all wires inside OEM-style, split-plastic loom, and uses nylon ties to secure the loom. Either way, nylon or zip ties eliminate the possibility of wires rubbing through the insulation, causing a short.

Support Group

Never rely on the wire's end connector to support the weight of the wire. Use an insulated metal or nylon clamp to support a wire--to the alternator--to stop any vibration that could cause the connection to fail.

Crimp Cocktail

Some wiring pros rely on soldered connections, protected by a heat-shrink insulation. Good choice, but also a labor intensive one. Painless insists that standard crimp connectors work just as well and are less prone to breaking or loosening by vibration. The keys to reliable crimp connections are a good-quality crimp tool and not overcrimping.

Fixing a Hole

When running wires through a panel, such as a firewall or an inner fender panel, always use a rubber grommet around the edges to protect the wires from abrasion. Also, if a wire or battery cable comes anywhere near a framerail or potentially sharp edge, cover it with a short piece of heater hose or vacuum tubing.

Take Your Time

You'll enjoy your car for years, especially if its electrical system runs smoothly. So, take a slow, cautious approach to installing your wiring kit. Measure everything twice. Double-check all connections. Consult the instruction booklet and wiring diagram often.

In the accompanying photos, we've illustrated the basics to show you just how, uh, painless it is to wire a Cobra kit car.