How to Troubleshoot Car Heater Problems

You’re on the road for a few minutes before you notice a chill. You realize the car heater isn’t working. This frosty scenario makes driving on a cold day miserable. It’s a problem our Kennedy Transmission car mechanics take care of every winter here in Minneapolis, MN.

What makes a good heater go bad? It could be one of several key components. When you turn on the heater, coolant moves through hoses from the engine and radiator to your vehicle’s heater core.

The heater core looks like a small radiator positioned against the firewall. As heated coolant moves through the unit, fans disperse the warmth into your car’s interior.

Use these steps to troubleshoot your car heater.

1. Check the Coolant

Low coolant can’t reach the heater core and generate warm air. Dirty coolant blocks proper circulation. Take a look at the level and condition of your engine’s coolant supply.

2. Assess the Heater Core

Make sure heater hoses are in good shape. Their mounting fittings should be tight and show no signs of leakage. Hold your hand above the hoses close to the firewall. If they aren’t hot, you may need to replace the heater core.

3. Inspect the Water Pump

A faulty water pump won’t circulate coolant through the system and back to the heater core. If the pump makes whining sounds or leaves wet spots on the garage floor, it could be the reason your heater doesn’t keep the car warm.

4. Listen to the Fan

If an air vent is not working, turn the heater and fan settings up all the way. Flip on the heater switch, and listen for the fan to engage. If it doesn’t come on, your heater problem could be somewhere in the car’s electrical system.

5. Look for Blown Fuses

Blown fuses can also result in heater trouble and result in air vents not working. Your owner’s manual is your best reference for finding fuses that drive the fan motor and control the heater switch. Most fuse boxes are located under the hood or under the dash just left of the steering wheel.

We’re Here Year-Round

We want you to stay warm on the road, so let our expert car mechanics check that heater. Drop by our Minneapolis, MN, shop or any of our Kennedy Transmission locations state-wide. We’re here year-round for all your automotive needs. If you are interested in reading more about our services and repairs, click here!

Recent Posts
Skip to content