Why Is My Ignition Key Hot? (11 Reasons Why)

You arrived, parked, and took your key out, only to be overcome by the heat. You’re frightened now that the key is too hot to touch. But, what might be a problem?

Having a hot ignition key is troublesome, especially since you might think that your car might blow anytime. So let’s discover more about why this is happening to your vehicle!

Why Is My Ignition Key Hot?

Your car’s ignition key gets hot because of a bad connection somewhere in the system, such as an open switch or faulty grounding somewhere else. Other reasons could be overheating solenoid, faulty ignition switch, and ignition relay. In addition, malfunctioning or disconnected battery cable could also add up to why your ignition key is heating up. 

Learn more about why your ignition key is getting hot. Here are 11 reasons why. Continue reading!

1. Faulty Grounding

Electrical grounding is essential for an automobile to function. Speak to an experienced automobile electrician because electrical systems are complicated.

The expert will inspect, trace, and guarantee that all grounds are in good shape.

If not, they might be the root of the heat resistance. Heat then builds up and travels to your vehicle’s ignition key.

2. Overheating Solenoid

The solenoid activates when your car is moving to stop you from unintentionally removing the key while you’re behind the wheel.

The solenoid naturally warms up, and the extra heat is transferred into the key’s metal shaft.

After your drive, the key will feel warm to the touch. It is typical for both Honda and other car makers.

3. Faulty Ignition Switch

A malfunctioning switch creates faulty connections. A switch should also be able to interact with the ignition cylinder across a lever or a shaft.

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In the absence of such, a high-resistance attachment is used. Unfortunately, it produces a lot of heat, eventually reaching your key.

Your automobile may even crash while it is in motion due to a malfunctioning ignition switch. Allow a mechanic to inspect all electrical systems to prevent that. If not, think about switching the switch.

4. You’re Driving A Hybrid Car

You are driving a hybrid car with a regenerative braking system—instead of using friction brakes as conventional vehicles do.

And suppose you’ve been going for longer than usual without charging up the battery pack in your hybrid’s electric motor and generator.

In that case, it will overheat because it hadn’t had enough time to cool down yet after stopping from high speeds or rapid acceleration/deceleration at those speeds repeatedly throughout its lifetime.

5. Faulty Ignition Relay

A poor connection can form inside an ignition relay with rust, corrosion, or water, generating a lot of heat.

Frequently, you notice that the plastic relay cover has already melted. If you’ve ever smelled burnt electronics, you should check the ignition relay next time you get that sensation.

6. Dirty Ignition

Dirty Ignition

A dirty key is the most common cause of an ignition key that gets hot. The dirt can cause the airflow through the key to be restricted, making it harder for the key to turning all the way around.

Another reason your ignition key might get hot is that there’s too much moisture in the air or on the ground where you’re parked or driving.

If there’s too much moisture in the air or on the ground where you’re parking or driving, it will result in rust on your car parts, such as engine parts and other metal parts attached to your car.

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In addition, it can cause corrosion inside these metal parts, which causes them to rust and get hot when exposed to moisture like dew or rainwater.

7. Faulty Battery Cable

A faulty battery cable can cause your ignition key to get hot. It happens when the cable is not working correctly and loses its ability to supply power to your vehicle.

The result is that your ignition gets too hot and damages it. In addition, your battery cables have become disconnected from the battery itself.

Or you’ve left them disconnected for an extended period without turning off the car or disconnecting them from each other first (this will hurt both your battery and spark plugs)

Of course, the ignition key will get hot if the battery cables are not connected to the correct terminals. When this happens, you must replace the battery cables with new ones.

8. Faulty Ignition Lock Cylinder

Another possibility is that you have a faulty ignition lock cylinder. These cylinders can get stuck inside the cylinder, which may cause them to heat up and burn out.

If this happens, you’ll need to replace them with new ones from a dealership or mechanic shop.

9. Your Car’s Engine Is Overheating

The engine needs to be adequately cooled, and your ignition key is one of the most direct points to do that.

If your key gets too hot, you can ensure that it’s not just your car’s engine that’s overheating by checking the temperature of your key with a thermometer before you go out and drive.

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10. Inappropriate Way Of Using Ignition Key

If you are misusing your ignition key, such as leaving it in a hot car or on your desk at work instead of locking it up somewhere, this will cause problems.

The temperature of the key should be kept between 110°F and 120°F. If this isn’t happening, there might be a problem with the connections between the key and its lock mechanism.

It can lead to corrosion or corrosion-resistant materials instead of stainless steel.

11. There’s Moisture Inside The Ignition System

The ignition key gets hot because there’s water inside it—like if your steering wheel was wet when you drove over some puddles during monsoon season.

Water is conductive, so when it mixes with things like lead, zinc, and other metals found in most keys, they heat up quickly and start melting into oblivion.

To learn more, you can also read our posts on why you can’t pull your key out of the ignition, why your key fob doesn’t work after replacing battery, and car alarm goes off when unlocking with key.


A hot ignition key is typically familiar, and you don’t need to take any action. However, you intervene when your ignition system is fundamentally flawed, or the key is extremely hot.

If your automobile is hard to start or frequently stops for no apparent reason, there may be an issue that must be fixed immediately.

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