Update 4/16/2012: GPS jammers are illegal and should not be used. After several events in recent years the US government has really began to crack down on GPS jammers since they pose a significant risk to public safety and national infrastructure. Consumers should not buy these devices unless they are approved by the FCC. Any jammer in use should be retired and an alternative method to ensure location privacy should be employed since penalties for jammer use could exceed $100,000 and include jail time.
With all this talk about how the police sometimes can and sometimes cannot use GPS tracking on your car I did a little research to see if there was something that a private citizen could do to prevent such activity from occurring. There is – it is called a GPS tracking blocker. What this device appears to be is a sort of signal scrambler that will confusing the tracking unit, making your vehicle “invisible” to the satellite eyes in the sky.
How Does a GPS Blocker Work?
As stated above, the blocker will work by emitting a signal that interferes with the signals transmitted by the Global Positioning System that orbits the earth overhead. The effectiveness of these blockers is only a few meters, so making sure that you place your device in such a way that it will be able to block a device placed in the front or back of your car is important. If you are driving a large tractor trailer and there are tracking devices installed somewhere in the trailer section then your blocker is probably not going to work. Also, if you have a particularly large SUV or truck be sure that your blocker is going to have a radius that will cover your entire vehicle.
The signal that the GPS tracking blocker emits is 1/1000 of the radiant energy that a cell phone transmits so you can be sure that these devices are much safer to have near you than a cell phone. Speaking of which, it is important to note that these devices will block regular navigation GPS units from working properly but it will not block the signal from a cell phone. What this means is that if you cell phone uses some form of alternative to GPS to get its position information you are going to need to buy a cell phone signal blocker if you don’t want people knowing where you are because of your cell phone.
A Word On Criminals
Now I want to be clear, I don’t want any criminals to be buying cell phone blockers or GPS blockers so that they can go do some sort of illegal activity. That is just wrong and I don’t want that to happen.  But I do know that there are going to be some law abiding citizens out there who don’t want the government to be able to tell them what they should and where they should be and who they should be associating with. They want their private life to be their private life and they want to have it without the threat of the government knowing everything about them.
GPS blockers are for this type of person. They obey the law, they just don’t want the law breathing down their necks.
Where Can I Buy A GPS Blocker
Amazon offers a pretty limited selection of GPS tracking blockers that can be found here:
- High Power GPS Blocker with AC Adapter and Car Charger (110V-220V)
- Super Mini Cigarette Lighter GPS Blocker
- High Power GPS Blocker with AC Adapter and Car Charger (110V-220V)
These device are certainly not very cheap and range anywhere from $50-$150. They do seem very sturdy and able to withstand a lot of wear and tear, but anything with an antenna like the ones found on these devices needs the antenna to be in good working condition if it is to block the signals the way that you want it to. I personally have not tested any of these GPS tracking blockers myself, but they do seem like they should work. If you have one or try one out, I’d love to hear about it in the comments below.
I have tried the GPS blockers and they work just as advertised. But, not for very long. They aere cheap pieces of electronics from China and will work about 5/6 hours total time and then stop working. It is probably from the heat it generates. It gets very hot in about 15 minutes of use.
Hi Carl,
Thanks for the information! I know that these devices are less than legal for companies inside the US and Europe to produce. I think mainly because of Western fears of their use for illegitimate activity if used in certain ways. I don’t think they are illegal to have in your possession, however.
How have you been using it? To stop tracking of your car? Or to block tracking at your home?
– Joe
will it work if the car is turned off? does it need constant power from the cigarette lighter?
thanks!
Hi John,
As far as I know the car would need to be on for the cigarette lighter to actually work – at least it is that way with my cell phone charger on my Honda Odyssey. But I expect that if your cigarette lighter works without your car turned on then the GPS blocker would work as well.
– Joe
far I have purchased several of these Blockers and I am still being stalked. One of my cars has two blockers in it and I do not think it is working. It is terrible that tracking devices are being used by any and everyone who thinks can can invade a person’s personal life. There needs to be laws now that address these issues. Because Civil Rights are being violated off the chain and law enforcement are the biggest crooks. I would like to know where in the OBD-II port these tracking devices are placed? I want to remove it! The GPS Blocker in the lighter just isnot working! What does PIN 5 Signal Ground mean this is on the connecter?HELP!
Hello Llinda,
The OBD-II port is often right under the steering wheel. And I am sorry to hear that the blocker in the lighter isn’t working. I heard from another commenter that the effective life of these blockers is short since they burn out after a couple hours of continuous use. I hope you can find something that will protect your privacy from these people who are obviously breaking the law.
– Joe
I have a marcus unit, how do you know what freq. to jam?
Hi Jeff,
You might want to check this out: GPS Signal Frequencies
do u have a rep i can talk to
Hi Joe,
The reason I want one is because my Step Daughter has a very violent boyfriend that wants to know where she lives and she wont tell him. The problem is he knows where she works and I am afraid he will put a tracking device on her car while she is at work and find out where she lives by tracking her. I wanted a gps blocker to counter that
Hi Bill,
I certainly can appreciate that, but owning a GPS blocker is against the law and I can’t recommend it. Maybe there is a better way to keep her safe?