Heated car seats can be great for cold winter mornings, but they are not immune to issues. The most common problem with a heated car seat is that the heater element breaks. It is quite rare for the actual heat switch to break. To determine if the heater element is broken, you will need to take apart the entire seat so this is the last thing you will check. There are several easy fixes and things to check first.
Step 1 - Start Easy Checks
Checking a heated car seat is a car repair you can take on yourself. One of the first things to look at is if any fuses have blown. If there is a blown fuse then you can replace it and the seat will work again. You also should make sure the plug that connects the seat to the main wiring is plugged in and free of dirt or corrosion. Use a voltmeter to check the voltage on each side of the switch. If there aren’t 12 volts, then the switch is bad.
Step 2 - Check the Shifted Thermister
If the plugs and switches are fine then you will need to check the heating element. The thermistor may not be working properly. The thermistor will set the temperature of the seat and adjust the temperature to your setting. If the thermistor has shifted even a little bit, then it will not work properly. Your car manual will tell you exactly where the thermistor should be located. Normally when this shifts it will burn out the heating wire.
Step 3 - Check the Heating Wire
The most common problem is that the wire that heats up the car has burned out. This wire is very fragile and small and will break over time. If you see any burn spots in the fabric around the element, then there is a break in the wire. You will need to replace the wire.
Step 4 - Replace the Heater Element
Use an ohmmeter to determine if the entire element needs replacing or if only one section is causing a problem. A healthy wire will measure resistance on the meter. You will need a new element as this is much easier than repairing the old one again and again. Once it breaks it will be more susceptible to breakage.
Step 5 - Access the Element
Pull the seat out of the car. You will need to unbolt the seat from the car or slide it off its tracks. Detach all the wires before you actually pull the seat out of the car. You will need to separate the back and the base of the seat to access the elements. You will probably need a torx wrench and a screwdriver to disconnect the sections of the seat. Remove the cushion and leather on the base to get access to the heater elements. You will see the element on the back of the seat. Try and take as much off as possible before replacing the wire. Most elements are self-sticking. Make sure the wire goes on in the same place that the old element was.
Step 6 - Put Everything Back
You can now put the seat back together. Simply reverse what you did to take the seat apart. You will need to place the wires through holes in the base so you can connect the wires to the plugs and get power to your new element.