testingriver

Hey guys, having an issue with our 2014 Jeep Grand Cherokee Laredo trailer brake system. We tried to plug our camper into the 7 pin but quickly realized this has a factory USCAR style connector. We then purchased an adapter (USCAR to 7pin + flat 4). This this would solve our issue, we connected everything and no lights turned on the camper. After testing the Jeep's factory connector with a multi-meter we determined that we only had accessory power, no power from brake lights/turn signals/marker lights/brake. After digging around online, we found out that our Jeep would need to be flashed by the dealer to activate the trailer brake system. We were changed $100. Took it home hooked it up and same story, no power, even when checked with a multi meter. We went back to the dealer and they swore up and down that it was activated and power was getting to the back. Am I missing something? We haven't purchased a new brake controller yet but that's on our list, just getting frustrated. Any help would be greatly appreciated. Cheers.

94zj318

If you have a TB on your Jeep, I can tell you it's definitely an aftermarket unit (Jeep has NEVER offered a factory TB on ANY Grand Cherokee). If you're having wiring issues with getting things to work, it might be helpful to have the manual for the TB so you can see which wires do what.

-Vince

testingriver

Hi Vince, thank you for the reply. Let me add that this Jeep came prewired for a brake controller (under the dash), including the wiring harness throughout the vehicle, from the factory. We received the schematics from the dealer showing the wiring diagram (relay/fuse to the connector). They also provided us a diagram of the connector pin designation. From my understanding, this year of Jeep, and probably newer, came from the factory prewired for a trailer brake system but the computer must be flashed to enable the trailer brake system as an option. Currently, we are waiting for our brake controller to be shipped, we doubt that connecting the brake controller will give us power to the 7 pin but we need to purchase one anyway. The last step will be taking this to a mechanic to diagnose the issue. In addition, the previous owner was nice enough to lose the manual. We'll need to download a manual online.

94zj318

Wow, I never knew these Jeeps came pre-wired for a TBC when you got the Trailer Tow Group. I've never owned a Jeep with the Trailer Tow Group unfortunately. I wish I did!