Cooler weather traditionally brings a familiar checklist for your car: check your battery, inspect your tires, and make sure the heater works. All good advice, but none of it is going to make someone stop and ask, “Wait, I’m supposed to do what?”

Some useful fall habits sound a little backward. Running the air conditioning when you can see your breath? Cleaning your car to help its safety features work? Apparently, cooler weather enjoys making everything more complicated.

Use Your Car’s A/C to Help Defog Windows in Cooler Weather

Your air conditioning can help clear foggy windows by removing moisture from the air, even when you’re using the heater.

That’s correct. The same button you leaned on all summer still has a job when the season of the sticks begins. Heat helps warm the glass, while the A/C system can help dry the air flowing across it. Some vehicles automatically activate air conditioning when you select defrost.

Follow your vehicle’s defrost settings rather than fighting the A/C light because “it’s already cold outside.” Compressor operation varies with temperature and system design, so it may not run in extremely cold conditions.

If the windshield stays foggy or airflow seems weak, there may be more going on than your car protesting the weather. You can investigate how your vehicle’s HVAC system works and what to check by opening your ALLDATAdiy subscription, selecting Systems and Components, and clicking Heating and Air Conditioning.

Keep Water Out of Your Car by Cleaning Drain Holes

Keeping your door’s factory drain holes clear allows rainwater to escape instead of collecting inside. Believe it or not, some water can get past the window seals and into the door, which is why drainage openings exist in the first place. When those openings clog with dirt and debris, your door can start holding water like a poorly planned aquarium.

As fall rain moves in, check the drain openings along the bottom of your doors for visible buildup. Follow your vehicle’s service instructions before removing plugs or inserting tools. ALLDATAdiy can help you find relevant water-leak troubleshooting information and applicable technical service bulletins.

Keep Your Car Clean to Help Its Safety Features Work

Dirt and debris covering your vehicle’s advanced driver assistance system (ADAS) cameras or sensor areas can interfere with the features that rely on them. You might be able to see around that collection of bug guts, but the camera behind your rearview mirror can’t lean over for a better look. Depending on your vehicle, cameras and sensors may also be located around the grille, bumpers, and mirrors, with some sensors concealed behind exterior panels. Obstructions can limit certain assistance features or make them temporarily unavailable.

When washing off fall grime, give these areas some attention instead of stopping once the windshield looks good from the driver’s seat. In your ALLDATAdiy subscription, find ADAS Quick Reference on the right to see information regarding your vehicle’s ADAS systems and locations if equipped. Follow your manufacturer’s cleaning precautions and avoid scraping or poking at sensitive components.

Not Adding Extra Antifreeze to Prevent Overheating

Using the manufacturer’s specified coolant mixture provides the intended protection; adding extra concentrate isn’t automatically an upgrade.
It sounds logical: the weather is beginning to get cold, antifreeze prevents freezing, so more antifreeze must be better. Unfortunately, your cooling system does not subscribe to the “little extra for good measure” cooking method.

Coolant needs the correct formulation and concentration. Ford, for example, warns that concentrations above 60% can reduce protection against overheating and may cause engine damage. That limit is an example, not a mixing instruction for every vehicle.

Check your vehicle’s requirements before topping off or changing coolant, and only open the system when it’s cool. A full reservoir alone doesn’t tell you whether the mixture is correct.

In your ALLDATAdiy subscription, select Specifications Quick Reference on the right side, then click Coolant to find the coolant specifications available for your vehicle. These may include the manufacturer’s recommended antifreeze/coolant-to-distilled-water ratio and protection temperatures. Follow the specifications for your year, make, and model rather than borrowing a mixture intended for another vehicle or climate.

Make Fall Car Care Work for Your Vehicle

The strangest fall tips often make sense once you understand what’s happening behind the dashboard or beneath the hood. The trick is knowing which advice applies to your car.

Use ALLDATAdiy to explore the procedures and specifications for your year, make, and model. Cooler weather already brings enough surprises. Your maintenance routine doesn’t need to contribute.