How To Activate trailer Lights on Jeep and Grand Cherokee

How To Activate trailer Lights on Jeep and Grand Cherokee

Jeep models are great little haulers. These workhorse vehicles were originally designed to operate in conflict zones, ferrying all sorts of cargo through tough battle zones. They can easily handle your average trailer. The problem? Even if you install a trailer light harness on your Jeep, the lights might not work. That’s probably why you are here. You want to know how to activate trailer lights on Jeep and Grand Cherokee models.

We have the information that you need, but you probably won’t like it. While it is possible to activate trailer lights on a Jeep, you will need to jump through hoops to get it done. 

How To Activate Trailer Lights on Jeep and Grand Cherokee

In this section, we want to go over how to activate the trailer lights on a Jeep and Grand Cherokee. Although, we can imagine that some of you may not necessarily be huge fans of the information that we give you here. This is because it isn’t something that you can really do yourself, even if you are decent as a mechanic. In fact, your average mechanic wouldn’t even know how to activate trailer lights on Jeep and Grand Cherokee models. Let’s explain.

Talk To Your Local Jeep Dealer

This cannot be avoided. If you did not purchase the trailer package when you got your vehicle, then the vehicle’s computer system won’t allow the Jeep’s lights to work. It is almost as if they don’t exist. You cannot activate that part of the vehicle’s lighting system yourself. You have no choice but to go and talk to your local Jeep dealer and ask them to switch it on.

This can cost money. Anywhere from $40 to $100, depending on the model of Jeep or Jeep Grand Cherokee that you have. However, this only needs to be done once, and it takes just a few minutes for your local Jeep dealer to switch the lights on.

Do bear in mind that because this is a process that requires access to a specific computer system, your local mechanic cannot activate the lights. The only people that can do this will be at the Jeep dealership. 

Make sure that the Jeep dealership shows you the lights working before you leave. Some people have had an issue where, even after activation, the lights didn’t work. 

Can You Activate Jeep Trailer Lights With An OBD-2 Scanner?

There are some guides that will tell you that you can use an OBD-2 scanner to activate the trailer lights on your Jeep and Grand Cherokee models. You cannot. Well, in most cases you cannot.

A Jeep without activated trailer lights doesn’t have the software needed to run those trailer lights. The OBD-2 scanner can only activate whatever features are there in the software. Nothing more. An OBD-2 scanner cannot install additional software on your Jeep. It doesn’t have the option to do so.

What the OBD-2 scanner can do, however, is get those trailer lights working if the trailer light software has already been installed, which is rare. You would know about it if you did (i.e. you would have trailer lights already). 

Why You Cannot Activate Trailer Lights on the Jeep and Jeep Grand Cherokee Yourself 

It pretty much just comes down to money. There isn’t any reason beyond this why you can’t install activate trailer lights on the Jeep or Jeep Grand Cherokee yourself. 

For most of their vehicles, Jeep charges extra to have a trailer wiring system installed. It can cost several hundred dollars more. They know that there are some people that won’t be wanting to pay that money for a trailer wiring system, and those people are going to install it themselves later on with a secondary market part. Of course, Jeep still wants their money.

Their solution is to charge people to activate their lights. It makes them $100, and they don’t really have to do anything. It means they still get a little bit of money from those that install trailer lights in their vehicle. Is it unfair? Yes. Not much that you can do about it, though. We suppose they are doing it under the guise of ‘caring’ about the parts that the customers install in their vehicles. 

Some Vehicles May Not Require Trailer Light Activation

Not all Jeep and Grand Cherokee models will need to have the trailer lights activated. In some cases, the lights will just work. No further fumbling about with the computer software. The only way to really tell is to install the trailer light harness yourself and test the lights. If they don’t come on, you either have a wiring issue, or you need to activate the lights. Unfortunately, it is pretty tough to tell what the situation is, mostly because when the lights are not active, they won’t be sending power through to the trailer lights anyway.

Most models pre-2010 are unlikely to need trailer light activation. It is a much more modern concept. 

Installing Jeep and Grand Cherokee Trailer Light Harness

Unfortunately, the trailer light harness installation will vary from Jeep to Jeep, so it is impossible for us to give you a complete guide here. However, you will need to remember the following:

  • You will likely need to remove and cut into your bumper.
  • You will need to ensure that your purchased light harness kit is compatible with your vehicle.
  • If the lights have not been activated, you cannot test them. 

We suggest that you watch a YouTube video for the installation of the light harness on your particular vehicle model. If you skip to the end of this page, we have included a fantastic video that shows you how to install a trailer light harness on the Jeep Cherokee from 2011 to 2021. You can see how involved the process is, and it may show you that talking to a dealership may be the best option. 


Unfortunately, if you want to know ‘how to activate trailer lights on Jeep and Grand Cherokee’, the answer is simple; you can’t. If you did not buy the vehicle with the towing package, then the lights can’t be activated by the average person or even the local mechanic. The only way to get the trailer lights working is to head to a Jeep dealership. They can tinker with the software on your vehicle and get the lights up and running for you. 

You will also like these other informative posts about the Grand Cherokee:


Why Are My Trailer Lights Not Working On My Jeep?

If you have just installed the trailer lights, then it is likely that the trailer light system has not been activated. You must talk to a dealership to activate it. If the lights previously worked, then you probably have a blown fuse. 

How Do I Know If My Jeep Trailer Lights Are Getting Power?

You can use a multimeter to test the Jeep trailer light wiring. Unfortunately, if the Jeep trailer lights have not been activated on a software level (only the dealership can do this), then there will never be any power running to the trailer lights. A multimeter won’t detect anything, even if it has all been wired up correctly.

How do I know if my Jeep/Grand Cherokee is Compatible With a Certain Type of Trailer? 

Several factors determine if your Jeep or Grand Cherokee is compatible with certain trailer types—the towing capacity on your car’s manual. Your vehicle should also have a hitch receiver to allow the trailer attachment and a wiring harness for the trailer lights. Also, you must install a compatible brake controller in your Jeep/Grand Cherokee for the trailer’s brakes. 

What Kind of Wiring Harness Do I Need for My Jeep/Grand Cherokee? 

Your vehicle’s model and year determine the type of wiring harness needed for your Jeep/Grand Cherokee. And also the kind of trailer you’ll be towing. The latest Jeep/Grand Cherokee models have a 7-pin wiring harness that includes trailer brake wires, turn signals, running lights and other features. Nonetheless, if your vehicle doesn’t have a factory-installed 7-pin wiring harness, you will have to invest in an aftermarket harness. Check out this video for more info:

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