Reproduction Wiring Harnesses for America's Muscle Cars M & H Electric Fabricators manufactures a complete line of exact reproduction wiring harnesses, battery cables and switches for Classic GM, Chryslerand AMCMuscle Cars. All of our harnesses are hand assembled to original OEM specifications to ensure a perfect fit in your classic Muscle Car.Chrysler · Products · OEM Manufacturers · How to Contact Us · FAQ Page · Custom Modifications 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.