Windshield Not Defogging Properly? Here’s Your Troubleshooting Checklist

To be able to see what’s coming down the road, having an HVAC and defrost system in good working order is vital.

That is, you should be able to turn on the defroster and watch the condensation dissipate within a matter of a few minutes or up to 15 minutes if ice is present.

If you experience excessive fogging or condensation and longer than normal defrost times, it’s an indication there may be something else going on. Here are three things you can do to make sure your window-clearing systems are functioning properly:

Check the Source of Moisture Inside the Cabin

What you keep inside your cabin may be where all that excess moisture and condensation is coming from. Water bottles and coffee cups, workout clothes, wet towels, shoes and pets can all contribute to increased moisture levels inside a cabin.

If there’s been a spill and liquid is present on a floor mat or upholstery, you’ll want to dry them as quickly as possible. Food waste that has been left inside your car should also be removed as it can sometimes cause moisture and unwanted odors.

The sooner you can identify these issues and take action, the easier it will be to keep a clear windshield.

Air Flow Restriction Caused by Clogged Filter

Cabin air filters can collect a lot of airborne contaminants during the summer and fall. If you haven’t changed this filter in more than a year, chances are it could be clogged and is restricting airflow when you are trying to defrost your windshield. In addition, a plugged cabin air filter that becomes moist may create an environment that encourages the growth of mildew and odors.

At a minimum, cabin air filters should be changed every 12,000-15,000 miles. In most trucks, these filters are located under the hood at the outside air intake along the firewall on the passenger side, where outside air goes through the filter before it comes into the cabin.

The ideal time to change a cabin air filter is typically after spring or fall when the filter has collected all that dust, dander and pollen and before winter and summer, when you’re likely to keep the windows up. Luber-finer cabin air filters help protect cabin occupants by:

• Trapping harmful allergens and pollutants before they reach the cabin
• Reducing difficulty with de-icing and fogging up of windows
• Providing cleaner cabin air that can reduce sneezing, blurry vision and headaches that result from pollen and other contaminants

Click here for more information on Luber-finer cabin air filters.

Heater Core Leakage

If you’ve removed the sources of moisture inside the cabin and checked the air filter, the other more problematic issue may be a malfunctioning or leaking heater core.

If you can smell coolant or see it leaking behind the dashboard, that’s a clear sign to get your vehicle inspected by a professional service technician