Monday, August 28, 2017

Don't stick a key or metal in 12v car outlet - Blown cigarette lighter fuse

The other day I was cleaning my car and I noticed it was dirty inside the cigarette lighter 12v electricity port. Without thinking I took my car key and started scraping the inside to try to clean it up a bit. Immediately there were sparks! I didn't even think about the fact that even though the car was off, there is still power supplied to this port and the metal key managed to trigger an electrical flow.

Luckily the key I was holding had a plastic rubber base so I did not get electrocuted but it still surprised me! I was hoping I did not damage anything serious. The car started up fine and other power features such as the power windows were working fine.

Then the next day I went to plug in my car charger for the phone and it did not work. So apparently the sparks did cause a problem. I did a little research and found out it was most likely a blown fuse. A fuse is a little thing that will break if it is overloaded with electricity which is what happened when I put the key in the outlet.

I looked them up and they are pretty cheap, only a few dollars. Also, it looked like it was easy to replace them which was nice. So I headed over to the auto parts store. I popped the hood to find the fuse box and the blown fuse. Sure enough, the fuse was clearly broken right in the middle.

I was thinking I would have to buy a new one but right in the lid of the fuse box, there were a bunch of spare fuses! The one I needed was there so I was able to swap it out right away without even having to buy a new fuse. I'm not sure if all cars have spare fuses like this, but in case you are going to change a fuse, check the lid in case there are any extras provided with the car.

So I put in the new fuse, plugged in the car charger and it was good as new! It was nice to have an easy car repair that did not cost any money for a change. Lesson learned, don't stick a key or anything metal in the cigarette lighter / 12v port even if the car is off.


  1. "This happened to my car too, but it wasn't the key that went into the charger socket, it was my charger cable. I was curious and tried to plug in the charger connector, but it suddenly got sucked in like a magnet and I had a hard time pulling it out. There was also a spark and the radio suddenly turned off, along with the dash cam. However, when I tried to turn on the car lights, they still worked, as did the car windows and the CR. I was worried if it had damaged my car."

  2. Phew, this just happened to me! I stupidly inserted my disposable vape into the charging port, just curious to see if it will fit there or not. The car was on and vape did fit perfectly in the port but it has a metal part at the end of it which led to a scary spark 😂.
    After a few google search I came across your post. It’s very useful and detailed. Thanks a lot. I will fix it tomorrow.

    1. My pleasure! Glad it was helpful.