A New Wiring Harness For Your Ride

By Stephen Kassis

1955-1956 Chevy Passenger Classic Update Harness

So you looked under the dash of your collector car or truck and it looked like a mass of spaghetti. Bare wires, cut wires, hanging wires, and burned wires are a red flag when dealing with a vintage vehicle. When restoring a 70-90 year old car or truck, it may be time to replace the harness. Ignoring the problem can have dire consequences.

If your vintage car or truck has broken or frayed wires, there is a high risk in not repairing or replacing the harness. Shorts in the electrical system can cause burned wires or even a total loss of the vehicle from fire. Early wiring harnesses used in Chevrolet cars & trucks, prior to 1949, were made with cloth covered wire. The cloth covering can become brittle and flake off, leaving the bare wire underneath exposed. If a metal object rubs up against the bare wire, shorts or even fire can result. Even if your vehicle has newer plastic wiring, it may have been damaged from previous modifications or a short circuit.

New harnesses are available for most Chevrolet cars & trucks. Original style harnesses are made with modern plastic coated wire which is covered in cloth covering. These have the look of original harnesses but with the safety of plastic coated wire. Also available are universal or Street Rod harnesses. These harnesses are made with a modern fuse panels and assembled with plastic coated wire. Some of these harnesses are made for specific applications like 1947-1955 Chevy Trucks, 1955 Chevy Cars, 1967-1972 Chevy Trucks, etc. Other kits are more of a universal application which provides a modern fuse panel with 13, 15, 20 & 22 circuit fuse panels. Some kits are complete upgrades and include the fuse panel, wiring, switches and fasteners. There are even some universal kits with cloth covered wire made to look like the original but with a modern fuse panel.

In addition to all of the above harnesses, there are a limited number of economy Chevy truck harnesses made with plastic coated wire, but do not look like original wiring. These harnesses will completely replace the original but without the original look. Economy harnesses are available for 1934-1959 Chevy trucks – specify if running the original generator or updated alternator.

Prior to 1949 passenger cars & 1960 trucks, original wiring harnesses were one-piece assemblies that ran from headlights to tail lights. After that original harnesses are segmented and must be ordered and replaced in multiple pieces.

Reproduction harnesses come with instructions for installation. They also have a numbering system on each wire to identify where it goes and a corresponding chart to make installation easy. A new wiring harness is an important investment in any restoration. It will keep your vehicle safe and operating properly.