Help your HVAC blower run at the speeds you select with the Dorman hvac blower motor resistor kit, part number 973-502. It pairs a new resistor with a harness pigtail to replace an overheated or corroded original resistor. It fits a range of Ford trucks and SUVs, among them the 2005-2007 Ford F-250 Super Duty, 2005-2007 Ford F-350 Super Duty and 2005-2007 Ford F-450 Super Duty. See the "Vehicles it fits" section for the full list.
The blower motor resistor sets fan speed by regulating the current sent to the blower motor at the lower speed settings. A blower that runs only on certain settings, or not at all, may need a new resistor, although other faults can cause the same symptoms. If a failed resistor or its connector is the cause, this kit replaces both together.
- Direct replacement: the resistor and harness kit is built to replace the original equipment on the listed applications.
- What's in the kit: each kit includes a resistor and a harness pigtail, which Dorman notes is essential for most repairs.
- Made to perform like original equipment: designed to return full HVAC blower operation when the resistor is at fault.
- Trustworthy quality: backed by Dorman's team of engineers and quality specialists in the USA.
- Position: front.
Before you replace any parts, diagnose the blower circuit to confirm the fault. When you install the new harness pigtail, follow your vehicle's service information.
Interchange: 4P1744 · RU1464 · 2C3Z19E624AA · 6C3Z19E624AA · 20611 · RU775 · JA1866
This part cross-references / interchanges with the following part numbers:
4P1744, RU1464, 2C3Z19E624AA, 6C3Z19E624AA, 20611, RU775, JA1866
Frequently Asked Questions
What does a Dorman blower motor resistor do?
It sets the blower fan's speed by regulating current to the blower motor at the lower speed settings. This lets the HVAC system deliver airflow at the speed you select.
What comes in the Dorman blower motor resistor kit 973-502?
Each kit includes a blower motor resistor and a harness pigtail. Dorman notes that the pigtail is essential for most repairs.
What are signs the blower motor resistor may need replacing?
Common signs include a blower that works only on certain speed settings or not at all, and an overheated or corroded resistor. Diagnose the blower circuit first, because other faults can cause similar symptoms.
Does it fit the 2005-2007 Ford F-250 Super Duty?
Yes. It is listed for the 2005-2007 Ford F-250 Super Duty, 2005-2007 Ford F-350 Super Duty and 2005-2007 Ford F-450 Super Duty. The "Vehicles it fits" section has the full list.
How do I install the harness pigtail?
Follow your vehicle's service information to remove the old resistor and connect the new harness pigtail. Disconnect the battery before working on the electrical system.
