Tesla Rear Defogger Not Working (8 Ways To Fix)

A Tesla rear defogger is a crucial part of maintaining visibility because it removes ice, frost, and condensation from the back glass. If your Tesla Rear defogger not working, you know how frustrating that can be. I just found myself in this challenging scenario, so I wanted to share my experience in the hopes that it will be beneficial for you if you are facing a similar issue.

I did some research and found that there could be a few potential reasons why the Rear defogger of your Tesla is not working.

In this article, I’ll discuss all the possible reasons why the Rear defogger of your Tesla is not working and provide you with some solutions.

How To Fix Tesla Rear defogger not working

There could be several causes for your Tesla’s rear defogger not to function such as a Faulty Switch, Faulty Relay, Fault in window coating, Blown fuse, Faulty electrical connections, Faulty heating elements in the rear window, Severe weather, or Software problems.

Here is a thorough detail of all these causes:

1. Faulty Switch

The button or switch that manages the rear defogger of your Tesla may be broken. The rear defogger will not operate if your switch is not providing the right signal to turn it on.

Solutions

You should visually check the switch for any wear, physical damage, or loose connections if you think it is defective. You should try turning the switch on and off several times to see if it responds inconsistently.

You should check the wires that link the switch to the rear defogger for any obvious damage, cracks, or loose connections. If you have a multimeter, you may use it to check the wiring and switch for continuity. 

Make sure the wiring harness is firmly linked at both ends of the switch and defogger in your Tesla. This will enable you to assess whether the switch is defective. If you find a problem with the switch, you should consider replacing it by yourself or through professional assistance.

2. Faulty Relay

A relay is an electrical part that switches a high-current circuit with a low-current signal. The rear defogger of your Tesla would not get the power it needs to work if the relay that is in charge of turning it on is broken.

Solutions

Usually, the fuse box of your Tesla houses the relay for the rear defogger. The fuse box is present in the front trunk behind the central black color plastic panel in your Tesla. To locate the specific relay for the rear defogger, you should see the owner’s manual or the diagram on the fuse box cover.

You can easily test the relay by using a multimeter and a known-working relay from another component of the car. If the new relay causes the rear defogger to function, this means, the old relay was malfunctioning.

 If you have found that the relay is defective, you should replace it with a new one. A replacement relay can be achieved via an authorized Tesla service facility, an auto parts retailer, or online. Make sure to purchase the appropriate relay according to your Tesla model.

3. Fault in window coating

Your Tesla rear window may have improperly applied aftermarket tint or coating that interferes with the defogger’s ability to work correctly. An improperly placed tint or coating may prevent the rear defogger heating elements from generating heat.

Solutions

You should start by carefully inspecting the rear window where the defogger lines are present to address difficulties with your Tesla vehicle’s rear defogger. You should carefully look for any evidence of deterioration, flaking, or faults in the window tint or coating. Make sure the coating or tint is tightly adhered to the rear glass surface of your Tesla.

You should remove the tint or coating temporarily from the region surrounding the defogger lines if you think it might be the source of the issue. You should use a heat tool to gently reheat the tint or coating which can help to remove it. 

You should be careful not to scratch the glass while doing this. To get rid of any leftovers, you should thoroughly clean the area with a light glass cleaner. You should test the rear defogger to ensure that it works properly without the tint or coating. 

If it functions properly, you can think about reapplying the tint or coating with the proper adhesives and techniques. You should seek professional assistance from a window tinting company for a tidy and efficient application.

4. Blown Fuse

Usually, a fuse provides power to the rear defogger system of your Tesla. The power supply to the system will be disrupted if the fuse that controls the rear defogger blows, rendering the system nonfunctional.

Solutions

You should open the fuse box of your Tesla vehicle that is located in the front trunk behind the central black color plastic panel and carefully look for any blown fuse. You will see a broken metal strip if the fuse is blown.

 If you find any blown fuse, it is the root of the problem. You should carefully replace the blown fuse with a new one of the same ratings. To prevent overloading the circuit, you should use a fuse with the correct amperage.

5. Faulty electrical connections

The electrical connections that supply power to the rear defogger of your Tesla may rust or become loose over time, resulting in a weak connection or no connection at all. 

Solutions

To ensure safety, you should turn off the engine of the car and unplug the battery. Examine the rear defogger lines of your car accompanying wiring and connectors both on the window and inside the car. You should check for any rusted and frayed wire or loose connections. If necessary, you should carefully clean or tighten the connections. 

Test the rear defogger of your Tesla after reconnecting the battery and starting the car. If the problem continues, you should think about getting help from a qualified technician with electrical system experience, as complex wiring problems could need specialized equipment and knowledge to accurately diagnose and fix.

6. Faulty heating elements in the rear window

The heating elements in the rear window are used to function the rear defogger in your Tesla. These components in your Tesla may deteriorate over time as a result of normal wear and tear, physical damage, or manufacturing flaws. Your Tesla’s window would not be effectively cleared by the defogger if the heating elements were damaged.

Solutions

First of all, you should locate the impacted regions by carefully inspecting the back window for obvious fractures or flaws in the lines. You will need to replace or repair any damaged heating elements. The broken components of your Tesla can be connected by conducting adhesive tasks using repair kits for minimal damage. 

Replacement of the rear window of your Tesla may be required for more severe damage, and this should be done by a qualified technician with experience working on Tesla vehicles to guarantee correct installation and operation.

7. Severe Weather

The rear defogger performance of your Tesla may be affected by extremely cold temperatures or harsh environmental conditions. Due to the severity of the frost or ice buildup on the rear window of your Tesla in very cold weather, the defogger could take longer to clear the window.

Solutions

You should park your Tesla car in a covered space or garage so it can warm up and the adverse weather’s effects on the defogger system can be minimized. Using a soft brush or scraper, you should remove any ice or snow accumulation from the rear window while being careful not to harm the defogger lines.

Turn on the rear defogger and wait for it to begin operating after cleaning your window. If it still doesn’t work, you might need to wait till the weather is more agreeable for the defogger system to function properly.

8. Software Problem

Different systems are managed by software in electric vehicles like your Tesla. Your rear defogger can stop working as a result of a software bug or problem. A software update or reset might be required to fix your problem.

Solutions

You should conduct a soft reset by simultaneously pressing the two steering scroll wheels until the touchscreen turns dark and the Tesla logo appears. It may resolve simple software issues.

If the problem persists, there may be any pending software updates that may cause the issue. You can download the software updates by following these steps:

  • Connect your Tesla vehicle to a stable network connection.
  • On the touchscreen display of your Tesla vehicle, tap on the “Main Menu”.
  • There you will see an option for “Software”. Tap on it.
  • When you enter the software option, you will see any “Software update” if available.
  • If there is any pending Software update, you should click on the “Download and Install button “to install it.

Final Thoughts

So far, we have discussed all the possible causes and solutions for the Rear defogger problem of your Tesla vehicle. The problems and solutions are explained in this article. The solutions include

  • Replace the faulty switch
  • Replace the faulty relay
  • Reapply the rear window coating
  • Replace the blown fuse
  • Tighten the connection
  • Replace the damaged wires
  • Replace the rear window if the heating elements are damaged
  • Remove ice buildup from rear window
  • Park your Tesla for some time in moderate weather.
  • Download the latest software updates

We have described all these in detail and answered some questions that you might have in mind.

If you have something to share with us about this topic, feel free to contact us. We would love to hear from you.

Does the Tesla rear defogger turn off automatically?

Yes, the Tesla rear defogger turns off automatically after 15 minutes. You have to turn it on again if you want to defrost the rear window.

Does my Tesla rear defogger stop working due to a lower battery level?

Yes, a Rear defogger uses extra energy to warm up your vehicle and stops working if your Tesla is not charged to an adequate level.

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