A Painless harness (PN 10206)...
A Painless harness (PN 10206) was chosen since it's designed to fit '67-72 GM trucks. The kit comes with an updated fuse block and heavy high-temperature wire for years of trouble-free service.
New trucks, old trucks, farm trucks, and custom classic trucks are the current craze-for both utility and the fun of owning an affordable vintage vehicle. Whether yours was found resting in a barn or handed down from a family member, trucks have become sentimental favorites of the hobby crowd. And most, if not all, of these classic haulers needed (or will need) to be re-wired at some point.
Vintage-vehicle lover Dave Foerster discovered he had the desire for a classic truck. He went on the hunt for a solid-running, but affordable, truck that still needed a few finishing touches. He located a '72 Chevrolet shortwide-bed pickup that was waiting for the installation of an air conditioner. The A/C unit and all the parts came with the truck, but the wiring needed to be replaced. Since Dave lives nearby in Bedford, Texas (a Dallas/Fort Worth mid-city), he contacted the capable crew at Painless Performance, and they volunteered to help with the electrical harness installation for training purposes.
Mike Burke and Jeff Abbott...
Mike Burke and Jeff Abbott decided it would be a good idea to first remove the hood for maximum engine compartment accessibility.
For those of you who might have been reluctant to tackle the installation of a wiring panel, follow along with our story to see how (if you follow the instructions) you too can install a wiring panel and re-wire your own classic truck.
We wanted the side-marker bulbs to flash along with the turn signals-one of the two wires coming from the marker-light socket was attached to the park-light wire and the other was attached to the turn-signal wire. When the turn-signal wire is hot, current flows through the light and is grounded by the park light bulb filament. When the park light wire is hot, the opposite occurs, passing current through the turn filament of the bulb.
The original bulkhead connector...
The original bulkhead connector was in fairly good shape, even though the wires had been twisted into a mess.
The wires leading into the...
The wires leading into the alternator were burnt and exposed at the connector-a sure sign of how badly the harness needed replacing.
Dangling just above the passenger-side...
Dangling just above the passenger-side header was the original body ground-strap. Without the ground-strap connected between the engine and body, the gauges and other electrical items might give inaccurate readings (or not operate at all) due to losing their ground.
Another jumble of twisted...
Another jumble of twisted wire was found below the driver-side headlight. All these original wires will be removed and replaced with the new harness.
The easiest access under the...
The easiest access under the dash is with the bench seat removed. That was the next step for getting the truck ready.
Under the dash was a real...
Under the dash was a real mess of twisted and mismatched wires. Extra gauges mounted below the dash didn't help the clutter.
At this point all the original...
At this point all the original wiring was removed. The original fuse block was still intact but the fuses were corroded. The original fuse can't handle upgrades to the electrical system, such as power windows and locks, whereas the new Painless Performance kit will.
The new fuse block comes with...
The new fuse block comes with a larger bulkhead connector to accommodate the extra wires necessary for the added accessories. The harness kit comes with a template to aid in marking for enlarging the bulkhead hole.
Due to some structure behind...
Due to some structure behind the firewall, the hole was marked away from the master cylinder. A die grinder with a de-burring tool was used to enlarge the hole.
The bulkhead was held in place...
The bulkhead was held in place and new mounting holes were drilled. Installing the gasket on the connector helps prevent moisture and hot air from entering the cab.
The new fuse block, bolted...
The new fuse block, bolted in the original location, will be easily accessible if fuse service is ever needed.
Mike Abbott attached the engine-side...
Mike Abbott attached the engine-side of the connector and tightened the mounting bolt.
John Roberts, a Painless wiring...
John Roberts, a Painless wiring instructor, suggested to Mike possible routing of some of the engine wires. It is important to keep the wires away from sharp edges, hot parts, and moving objects.
John also illustrated how...
John also illustrated how the wires are all marked with their destination as well as the GM factory color code, a great aid in routing to the appropriate functioning part.
As added protection, plastic...
As added protection, plastic split loom was acquired and installed on the wires passing in front of the radiator.