I just had a hitch put on. The wiring harness runs from the battery, down the left side of the vehicle, clips into the left tail light, then goes just in front of the muffler on the left side. However, since they could route it to either taillight, if it's not on the left side check the right side as well. If you reach under the bumper you'll notice it has a lip. Check underneath there and see if they stuffed it up there. You could also get the Jeep up on ramps and follow the wire from the battery to see where they put it. If you absolutely can't find it, you have a few options. The stock MOPAR one is part number 82209280AD. Moparliquidators.com has it for $94.75. Since that's a bit excessive in my opinion, you can also buy one from U-Haul (they used part number 13493 on my hitch) which cost me $39.95.