1997-2001 Infiniti Q45 Blower Motor: Failure Symptoms & Resistor Diagnosis

Common Symptoms of a Failing Q45 Blower Motor

When a blower motor begins to fail, it usually provides several warning signs. Recognizing these can help you pinpoint the problem before it leaves you without cabin airflow. Here are the most common symptoms:

• No Air From Vents: The most obvious symptom is when you turn on the fan and nothing happens at any speed. This could indicate a completely failed motor, a blown fuse, or a faulty resistor.
• Weak Airflow: If the air coming from your vents seems much weaker than it used to be, even on the highest setting, the motor may be worn out and unable to reach its full speed.
• Unusual Noises: A worn-out motor bearing or debris inside the fan cage can cause various noises. You might hear a grinding, squealing, rattling, or persistent humming sound coming from the passenger side dashboard area.
• Burning Smell: A distinct burning odor from the vents when the fan is running can be a sign of the motor overheating, which is a serious symptom that should be addressed immediately.

Diagnosing the Problem: Motor vs. Resistor

Before buying a replacement motor, it's critical to determine if the motor itself is the problem or if the issue lies with the blower motor resistor. Wasting money on the wrong part is a common mistake.

1. Check the Fuse: Always start with the simplest solution. Consult your owner's manual to locate the fuse for the HVAC blower motor and inspect it. If it's blown, replace it and see if the fan works. If the new fuse blows immediately, you may have a short in the motor or wiring.
2. The High-Speed Test: Turn your fan to the highest setting. If it works on high but not on any of the lower speeds, the blower motor resistor has failed. The motor itself is fine.
3. Listen for Noises: If the fan works but makes grinding or rattling noises, the motor's bearings are likely worn out. In this case, the motor needs to be replaced.
4. Direct Power Test: If the fan doesn't work on any speed, the next step is to test the motor directly. This involves accessing the motor behind the glove box, unplugging its electrical connector, and using jumper wires to supply it with 12V power directly from the car battery. If the motor spins when connected directly, the motor is good, and the problem is the resistor, control unit, or wiring. If it does not spin, the motor has failed and needs replacement.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

As of mid-2026, there are no specific recalls or widespread Technical Service Bulletins (TSBs) issued by INFINITI or the National Highway Traffic Safety Administration (NHTSA) for the blower motor or blower motor resistor on the 1997-2001 INFINITI Q45. Failures that occur are typically due to normal wear and tear over time.

Buyer's Guide: What to Check When Purchasing a Used Blower Motor

A used OEM blower motor can be an excellent value, often offering superior quality and quieter operation compared to cheap aftermarket alternatives. Here’s what to look for:

• Verify the Part Number: This is the most critical step. INFINITI used different blower motors during this generation. Part number 27220-5P100 is typically for models built up to April 1997, while 27220-5P108 is for models built from May 1997 onward. Always match the part number from your original unit to the replacement.
• Physical Inspection: Look at the electrical connector pins. They should be clean and free of any green or white corrosion. Avoid any units with melted plastic on the connector, which indicates a severe electrical issue.
• Spin the Fan Cage: Turn the squirrel cage fan by hand. It should spin smoothly and silently with minimal resistance. If you feel any grinding, notchiness, or hear any noise, the bearings are worn, and you should pass on the part.
• Check the Fan Cage: Inspect the plastic fan blades for any cracks or missing pieces. A damaged or unbalanced cage will cause significant vibration and noise when installed.
• Look for Water Damage: Check the metal motor housing for excessive rust or water stains. A leaky heater core or evaporator can drip onto the blower motor, causing premature failure.

Cost Comparison: New vs. Used Q45 Blower Motor

Prices can vary based on supplier and condition. Here is a general cost expectation:

Installation Guide

Difficulty and Time

• Difficulty: 2/5 (Easy to Moderate)
• Estimated Time: 1 - 1.5 hours
• DIY Feasible: Yes, this is a very manageable job for a DIY mechanic with basic tools.

Tools Needed

• Ratchet with extension
• 10mm socket
• Phillips screwdriver
• Trim removal tool (optional)

Step-by-Step Replacement

The blower motor is located behind the glove box on the passenger side.

1. Disconnect the Battery: Always disconnect the negative battery terminal before working on electrical components.
2. Remove the Glove Box: Open the glove box and remove the screws holding it to the dashboard. There may be screws along the top, bottom, and sides. Once the screws are out, carefully detach the glove box assembly and set it aside.
3. Access the Blower Motor: Behind where the glove box was, you will see a plastic panel or 'back wall'. Remove the screws holding this panel in place to expose the HVAC unit. The blower motor is the round assembly, typically on the right side.
4. Unplug and Remove: Disconnect the electrical connector from the bottom of the blower motor. The motor is held in place by three screws. Remove these screws, and the blower motor assembly will drop down.
5. Install the New Motor: Position the replacement motor, secure it with the three screws, and plug in the electrical connector.
6. Test the System: Reconnect the battery and test the fan at all speeds to ensure it is working correctly before you reinstall the glove box and trim.
7. Reassemble: Reinstall the access panel, glove box, and any other trim you removed.

Frequently Asked Questions (FAQ)