I'm new to my Grand Cherokee and wanted to install a hitch and harness to tow my 6x12 trailer. I just installed a Reese hitch without issue. My question is shouldn't my Cherokee have a factory harness behind the bumper? I couldn't find the plug. I was hoping to use the factory one and have the dealer activate it. I also saw the Curt and Tekonsha 4 pin wiring kits and will do this if I have to. Thanks.