Automotive Wiring Harness Repair, Wire Harness for Car Types of Wiring Harness. If one of your car's gadgets or devices isn't working, one of the likely reasons for that is a malfunctioning or defective wire harness. That shouldn't be too big of a problem though since you can always replace a wire harness. But before you buy the first wire harness that you see, make sure it's the right kind first Exact OEM Reproduction Wiring Harnesses for Classic Our wiring harnesses are brand-new and better than N.O.S. (new old stock) THE PROBLEM: Let's face it folks, NO automobile manufacturer ever designed a wiring harness to last 30-60 years. As a matter of fact, your vehicle's original wiring was only designed to last 10 years before it started to deteriorate! There is ample documentation to substantiate this claim.