Why Your Car Heater and Defroster May Stop Working

Car Heater, HVAC system, Defroster

Why Your Car Heater and Defroster May Stop Working

Car Heater, HVAC system, DefrosterAs you probably know, winters in Michigan can be COLD. If you have noticed any noises or smells coming from your vehicle’s heating system, now is the time to track down those issues. Let’s explore some common factors that may affect your car heater, defroster, and HVAC system.


Common Issues With A Car Heater and Defroster

Driving in a cold vehicle is uncomfortable and can also be dangerous. A fogged-up or frosted-over windshield becomes hazardous if the heating system is malfunctioning. Additionally, prolonged exposure to freezing temperatures while driving negatively affects driver response times. Let’s review some common reasons why your car heater or defroster isn’t working. We will explore mechanical malfunctions, electrical problems, and maintenance issues.

Mechanical Malfunctions

If you suspect a mechanical malfunction with your car’s HVAC system, schedule a diagnostic service with your auto technician. Their diagnostic equipment can quickly locate the issue, saving you time and frustration. They can also advise you on which components need repairing and which require replacement.

Heater Core: A clogged heater core may produce a sweet odor or leaking coolant and require replacement.

Heater Fan: A broken heater fan cannot move warm air through the vents into the vehicle’s interior.

Heater Thermostat: A faulty thermostat may not turn on or off when needed, allowing cold air to exit the vents instead of warm air.

Blend Door: A stuck or dislodged vent blend door results in a heat-flow issue (too much or too little). 

Electrical Problems

Your owner’s manual is a great resource for troubleshooting electrical problems in your car’s HVAC system. Many times, replacing a simple fuse will fix the issue. If you prefer to leave the repairs to your service technician, make an appointment and let them know about your electrical problems.

Blower Motor: A blown fuse will disable the blower motor and need replacement.

Rear Defroster: The rear defroster is electric and not dependent on the cooling system. Inspect the electrical connections, wires, and fuses to discover the problem.

Maintenance Issues

Performing routine maintenance as outlined in your owner’s manual can help prevent HVAC system issues. However, unintentional delays or unexpected factors can create problems that require immediate attention.

Leaking Coolant: Heated air from the heater core will only blow into the cabin with sufficient engine coolant levels.

Front Defroster: Dirty or clogged vents along the windshield will prevent defrosting due to inadequate airflow.

Dirty Cabin Air Filter: A clogged cabin air filter is to blame for musty odors and restricted airflow from the heater vents.

Car Heater & HVAC Service, Maintenance & Repair

Driving your car without a functioning heater is no fun! At Ron’s Garage, our service technicians will diagnose, repair, or replace your vehicle’s HVAC system. Ask us about our 3-year/36,000-mile warranty and free shuttle service!

Make An Appointment

Schedule an HVAC service with Ron’s Garage to stay safe and warm while driving this winter. Call us at (734) 961-4701 or visit our website to set up your appointment for your auto’s HVAC: Car Heater or Defroster.