GM Truck Blower Motor Resistor Replacement

By the Radman Auto Repair team, independent auto repair in Etobicoke since 1999 · Updated November 2026

On 2007–2014 Chevrolet and GMC trucks and SUVs, the part that controls fan speed fails often. The fan works only on high, stops working, or runs with the truck off. The connector often melts too.

Symptoms

What Causes It

Before You Start

• Park on level ground, set the parking brake and chock the wheels. Never work under a car held up only by a jack: use rated jack stands.
• Let the engine and exhaust cool before you touch them; coolant systems are under pressure when hot.
• Wear safety glasses and gloves, and disconnect the 12V battery before unplugging electrical parts or working near airbags.
• Check for open recalls on your VIN (Transport Canada or the manufacturer’s site) before you buy parts: a recall repair is free at the dealer.
• Disconnect the battery before cutting or splicing wires.

Step-by-Step: GM Blower Motor Resistor

1. Find it. Look under the dash on the passenger side, beside the blower motor.
2. Check the connector. Unplug it and look for melted plastic or brown terminals.
3. Remove the part. Remove the screws and pull the resistor or module out.
4. Replace the connector if needed. Cut out a melted plug and splice in a new pigtail with good crimps and heat shrink.
5. Install the new part. Fit the new resistor or module and plug it in.
6. Test the blower. Check every fan speed. With a clamp meter, check that the blower motor’s current draw is normal; replace a worn motor.
7. Check key-off. Make sure the fan stops with the key off.

When to Stop and Bring It In

• The new part fails quickly: the blower motor is likely worn.
• The fan doesn’t run at all even with a new part: check the fuse and blower motor.
• You see melted wiring beyond the plug.
• There’s no heat even with the fan working: see heater blowing cold air.

Not sure, or out of time? Radman Auto Repair in Etobicoke does this repair every week. Book online or call (416) 742-4521.

Also Known As

Searched as “Silverado blower only works on high”, “Tahoe blower motor resistor”, “Sierra fan won’t turn off”, “GM blower motor control module” and “melted blower resistor connector”.

Frequently Asked Questions

See also GM, Chevrolet & GMC Repair, Heater Blowing Cold Air, Car A/C Repair, Electrical Diagnostics.

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17:17 23 Jun 26

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