Dorman 973-503 HVAC Blower Motor Resistor Kit

HVAC Blower Motor Resistor Kit for GM Applications

Dorman 973-503 is an HVAC blower motor resistor kit that replaces an overheated or corroded original resistor and includes the matching harness pigtail. It is built for direct repair on select Chevrolet, Buick, Oldsmobile, and Pontiac vehicles with manual blower speed control.

Key Features

• Includes a blower motor resistor and wire harness for a complete electrical repair
• Uses a 4-wire harness with blade terminals and a female connector
• 16-inch wiring harness length for service replacement routing
• 3 mounting holes for OE-style installation points
• Direct replacement for select GM HVAC blower motor resistor applications
• Cross-references Dorman 973-503 applications with common OE-style numbers such as RU49 and RU870

Detailed Product Overview

This Dorman 973-503 blower motor resistor kit is made for vehicles where the original resistor has failed from heat damage or corrosion at the connector. It restores blower motor speed control by replacing the resistor and the damaged harness pigtail together, helping address the electrical wear that often causes intermittent fan operation. Compatible With 1988-1996 Buick Regal, 1988-1996 Pontiac Grand Prix, 1989-1997 Oldsmobile Cutlass Supreme, 1995-1999 Chevrolet Monte Carlo, and 1995-2001 Chevrolet Lumina, this part supports common GM HVAC repair needs across multiple model years.

Common Problems This Part Can Address

• Blower motor works on only certain fan speeds
• HVAC fan stops responding because of a burned resistor
• Connector damage from heat, corrosion, or melted terminals
• Intermittent cabin airflow caused by electrical resistance at the harness
• Loss of blower control in manual HVAC systems

Installation Notes and Tips

Inspect the connector, terminals, and surrounding wiring before installation. Replace any heat-damaged or corroded wiring at the same time so the new resistor is not exposed to the same failure point. Verify the vehicle uses the listed manual HVAC configuration; 2000-2001 Chevrolet Lumina applications exclude climate control. Confirm the mounting location and connector style match the original part before installation.

Quality Assurance

Dorman supplies this resistor kit as a service replacement for select GM HVAC systems, with the resistor and harness pigtail packaged for repair of the original electrical connection. Part number 973-503 is also referenced in aftermarket catalogs under RU49 and RU870 for the same application family.