If you know your street machine, you might feel like youre actually wired right into its main engine harness. That would actually be very cool. But whether youre hardwired or not, youd want to make sure that all those electrons made it to their intended destinations as easily as possible. Thats what your wiring harness does for you. After 30-odd years of heat, vibration, abrasion, and abuse, the harness that connects your car to your engine might be in need of salvation.
The obvious answer is to bolt in a new wiring harness and be done with it. If you are knee-deep in a 60s or 70s musclecar restoration, thats the hot ticket. But most Chevy High Performance readers are more interested in modifications rather than pure restoration. With a minimum of effort, you can order just about any kind of modification into your wiring harness that youd like. This means a small increase in cost over a stock harness, but its worth the investment.
We focused our attention on the engine harness since thats where we centered a majority of our modification ideas. We contacted M&H Wire Fabricators to get connected into the details of wiring harnesses. M&H has been making replacement wiring harnesses for musclecars and classic vehicles for years using exact replicas of the original connectors to give restorations that factory-fresh look. These same harnesses can be used for hot rods as well.
For example, M&H constructed a harness for our 67 RS street-driven small-block Camaro. We planned on several engine compartment changes including the addition of an aftermarket ignition system that would require 12-14 volts to the ignition coil. M&H also offers a one-wire electronic-ignition conversion that, when the distributor cap is in place, looks just like a points distributor.
A very popular modification to many early Chevy musclecars is a charging system upgrade. The older, external regulator alternators are on the weak side compared to todays 90-amps-at-idle wonders. M&H offers both add-on connectors that will convert your existing harness, and a new engine harness that will incorporate these changes directly into the existing harness. M&H can supply connectors even for the most recent CS-130 and large CS-144 alternators. These latest-generation alternators can crank out some serious amps to power even the most electrically challenged street machine.
Another electrical addition that might be useful includes connections for an electric fan and relay. Electric fans generally pull in the neighborhood of 15 to 30 amps, which requires a relay. This allows a light-duty switch to control the relay that actually connects power to the electric fan.
As you can see, there are many ways you can customize your street machine with electrical goodies that still allow it to look much the way it did when it rolled off the assembly line. Or you can electrify your ride with all kinds of outrageous electronic goodies that are state-of-the-art 21st-century cool. Either way, your own creativity is the only limit.