On most full-size GM trucks and SUVs from 2001–2007, the blower motor resistor has two common failure modes: water damage and excess heat. The GM vehicles are unable to manage condensation. If the duct is clogged, condensation will collect, creating a pool of water that can seep into, and flood the blower motor resistor module. Worn OE blower motors can create a demand for current that also damages the module. The excess current melts the wiring and plastic shroud, damaging the interface pins on the controller’s circuit board.
NAPA® Echlin’s RU631 Blower Motor Resistor features several improvements over the OE, including an umbrella cover design that prevents water intrusion and a larger-output power device and upgraded two-ounce copper board that protects against overheating.
Larger output power device mounted directly to heat sink improves heat dissipation
Improved umbrella cover design prevents condensation from entering module
RTV sealant around heat sink and cover perimeter prevents water intrusion
Manufactured in the USA
Upgraded 2 oz. copper board increases conductivity and power dissipation to prevent overheating
Included wire harness undergoes voltage drop testing to ensure performance
In this "Installation Spotlight" video, our ASE-certified Master Technician is working on a 1993 Jeep Cherokee with a blower motor that only works on the high position. Here's how to replace it.