GMC R2500 Wiring Harnesses & Electrical - OEM-Fit Harnesses & Components

Restore your GMC R2500’s electrical system with precision-engineered wiring harnesses and electrical components designed specifically for your vehicle. Each harness is manufactured to match the original routing, connectors, and circuits of your GMC R2500—restoring the wiring behind the dash, under the hood, and through the body to factory-correct, or factory-improved, condition.

Our GMC R2500 electrical lineup includes complete wiring harness sets, battery cables and ground straps, switches, electrical devices, and update/conversion products such as alternator upgrades and electronic ignition conversions. Every component is manufactured and tested to deliver dependable, factory-correct performance, and is organized by your vehicle’s exact year to ensure the harness or component you order is the one built for your GMC R2500—not a close approximation.

Use the Vehicle Selector above to find the correct wiring or electrical component for your GMC R2500, or browse below to explore available options. Whether you’re chasing judging points with a numbers-matching restoration or simply getting your GMC R2500 running right, Factory Interiors makes it easy to restore your electrical system with wiring products proudly made in the USA.

1986-1989 GMC R2500 Rear Window Defroster Relay/Timer

-O.E.M. made using original GM tooling-, S15, except Pick-Up

$103.0
• SALE $102.95
Select Color/Material Options  
1986-1989 GMC R2500 Rear Window Defroster Relay/Timer
1973-1978 GMC R2500 Temperature Sending Unit

1973-1978 GMC R2500 Temperature Sending Unit, built to original specification.

  • Choose your exact application from the options above
  • Each option lists the equipment and fitment it covers

1973-1978 GMC R2500 Battery Cable Junction Block

-reproduction-, with auxiliary battery

1988-1989 GMC R2500 License Plate Light Assembly

-reproduction-, C/K series, Pick-Up, with license plate mounted on passenger side to factory installed trailer hitch, without step bumper

1977-1981 GMC R2500 Connector: Power Door Lock Switch

with 3 terminals in a triangular pattern (includes pigtail)

(76 Total Products)