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The Blower motor ensures the blowing of cold or hot air through the Air conditioner vents in the gmc sierra. A problem with the gmc sierra blower motor will make it unable to flow out the air of the vents. In that case, troubleshooting the problem ASAP could be a great relief. But do you know how to troubleshoot gmc sierra blower motor problems?

The faulty motor can be the major culprit for the gmc sierra blower motor not working. Troubleshooting the blower motor problems in gmc sierra is not much complex if you diagnose the problem. Once you identify the problem, it will be easier for you to fix it accordingly.

However, for the best knowledge and easy fixation, you should read my below blog. You will be provided with what causes a blower motor to fail and their solutions. You may also be interested in these articles: How to troubleshoot GMC Sierra stalling problems?

Guide on how to troubleshoot gmc sierra blower motor problems?

gmc sierra blower motor problems

Here have listed some of the most common causes and their solution which may cause gmc sierra blower motor problems.

  • Faulty Blower motor
  • Bad electrical connectors
  • Bad relay
  • Blown fuse
  • Bad resistor

Problem 1: Faulty Blower motor

A broken or faulty blower motor is the most common and major cause of 2009 gmc sierra blower motor problems.

You can identify the faulty blower motor by some early signs. Your blower motor fails without warning; unusual whirring noises, burning odor, smoke, and inconsistent airflow are some signs of a faulty blower motor.


Replacement is the best option when you have a problem with the blower motor. Most of the time, blower motors are irreparable, and if you repair them not work properly. But before replacement, ensures your blower motor is faulty.

Follow below the simple guidelines to test the blower motor in gmc sierra.

  • First, unplug the blower motor from the electrical connector.
  • Test the connectors, connect the connector with the multimeter and turn on the AC fans. I suggest you use Digital Multimeter Tester by OWUYUXI to get accurate measurements.
  • Check the reading; it should be 12 V. If the connectors show 12 V, you have a problem with the blower motor.
  • Connect the blower motor with a fully charged 12V battery for more confirmation. If the motor still does not turn, your motor is dead, and it needs replacement. I recommend installing AC Heater Blower Motor because it is highly compatible with chevy, gmc & other gm vehicles. It is so powerful and works excellently.

Note: Also, don’t forget to check the user manual and replace the battery as recommended by the manufacturers.

Problem 2: Bad Electrical Connectors

You have the electrical connectors on the resistor module, blower motor, and climate control unit. If there is a problem with the electrical connectors, these parts will not receive the electrical power.

Ultimately, they fail to perform their functions; resultantly, you will experience gmc sierra blower motor problems.


Test all the connectors with the multimeter and ensure all are working fine. If you find a problem with any connectors, replace them with new ones.

First, check the blower motor connector. Connect it with a multimeter and switch on the AC fans; if the voltage is 12 V, it is normal. If the voltage is low or zero, you have a problem with the connector.

After the blower motor connector, check for the resistor module and climate control unit connectors with a multimeter.  Replace which one has the problem.

Also, check for the wires; if connectors are in good condition but not showing voltage, you may have an issue with the wires. Check the wires; repair or replace them if they are broken or damaged.

You may also like: 2008 gmc sierra driver door controls not working

Problem 3: Bad relay

A bad relay can be the culprit for gmc sierra motor problems. Relay is responsible for switching the electrical loads on and off.

For the proper functioning of the blower motor, relay functioning is essential. You may have a problem with the relay if you see inconsistent airflow or power supply.


Generally, relays are located under the steering wheel on the left side or in the engine compartment. But you should read the manual to check for the particular model relay location.

Test the relay with other relays in the fuse box, but ensure you use a similar amp rating. 

If the relay is faulty, arrange for the new one and disconnect the old one from the battery. 

Replace the faulty relay with a new one and connect it to the battery. DTS New Blower Motor Relay could be your next try if your one becomes faulty.

Problem 4: Blow Fuse

The blower motor in gmc sierra needs the power to perform its blowing function. If the fuse is faulty, the circuit will break, and the blower motor will not receive the supply. 

A defective or blown fuse can be the culprit for the gmc sierra motor not working.  Immediately fix the problem to get your blower motor back to work.


  • Read the instruction manual provided by the manufacturers to know the location of the fuse. In gmc sierra, it is located near the blower motor.
  • Once located, check the wire inside the fuse; if the wire is broken fuse is blown
  • Replace the fuse with the new one, but ensure the correct amp rating

Problem 5: Bad resistor

bad blower motor resistor

The resistor is a major part of the blower motor that controls the blower motor speed. You can adjust the blower motor speed with the climate control unit. The climate control unit uses the resistor to control the blower motor speed.

If you have a problem with the resistor, you may experience the gmc blower motor resistor failing to manage the speed. Ultimately your blower motor will stall.


After replacing the faulty resistor, solve the gmc sierra blower motor problems. But before replacing, test the resistor to confirm it is faulty.

The resistor in the gmc sierra is located under the passenger dashboard.  Search it closer to the blower motor.

  • Once you have found it, remove the electrical connectors from the blower motor.
  • Connect the multimeter with the resistors and turn on the ac fans.
  • Check for the voltage on the multimeter; it should be 12V.
  • If the voltage is not the 12V, you have a faulty resistor that needs replacement
  • Replace the resistor with a similar amp rating resistor

Still Have Questions?

What is the signs gmc sierra blower motor resistor is faulty?

You may have a problem with the resistors if you see an inconsistent fan or blower motor speed. You may experience the too fast or too slow speed of the fan because of the inconsistent performance of the resistor.

Why is my 2009 chevy silverado 1500 blower motor not working?

2009 Chevy Silverado 1500 comes with a powerful blower motor that lasts many years. If it is not working, you may have a problem with a resistor, control module, bad relay, or blown fuse.

How to troubleshoot 2011 gmc acadia blower motor problems?

You may find out many causes for motor problems in 2100 gmc Acadia. But the most reported causes are bad resistors, electrical connectors, wiring, and fuse. First, check for the resistor, electrical connectors and wiring, and fuse.

Why is the 2005 chevy silverado blower motor not working on high?

Check for the resistor if your 2005 chevy Silverado blower is not working on high. When a resistor is faulty, it provides inconsistent performance.

Final Verdict

Sierra blower motor is powerful and long-lasting, but some problems may make the gmc sierra blower motor not work.

First, you should identify the cause of the problem and fix it accordingly. 

You can also take assistance from the user manual. Only go for the DIY solution if you are fully confident in your skills; otherwise, hire a professional mechanic.

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