s manual of your car to find the fuse box location and locate the fan fuse. Check the fuse, if it is still functional, the issue may be due to a faulty fan.

Method 4 of 4: Check for a faulty heater core

Step 1: Check for a clogged heater core. This component of the heating system is a smaller radiator located inside the car compartment underneath the dashboard. Warm coolant flows inside the heater core and when the heater is turned on, it transmits the heat to the cabin area.

When the heater core is clogged or dirty, the coolant flow is insufficient and that can diminish the heat inside the car.

Step 2: Check for a leaking heater core. Check the floor mats in the cabin and see if they are damp or if they have the smell of coolant.

When the heater core gets damaged, it will become very noticeable because the cabin area on the floor mats starts getting wet and the smell of coolant is present. This also leads to poor heating conditions.

  • Tip: Ensure that you check the air conditioning before those hot days of summer as well.

A heating system that functions properly is an important part of your car. Also, a broken car heater will adversely affect the performance of your car’s defroster, which in turn hinders visibility, and limits your ability to drive safely. If you notice any issues with your car’s heater, ensure that you perform a thorough check of the system and get any problems fixed at the earliest.

If you are not comfortable with performing this process on your own, get a certified professional, such as one from YourMechanic, to perform the heater inspection for you.

This article originally appeared on YourMechanic.com as How to Diagnose a Broken Car Heater and was authored by Jose Guzman.


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