Just got home from buying a 2016 Cherokee Trailblazer. Owners manual gives the necessary steps for towing + recommendation of having the Mopar wiring harness installed.
We educated the salesman and the sales manager to this fact thanks to information we took off this forum. Dealership checked and apparently we, the purchasers, have to deal with Chrysler to have this modification done. We have a number to call and make the arrangements. Was also told that Chrysler has been working on this problem for a while now and latest Jeeps are not having as much trouble as earlier models. Time will tell for us.
We sure appreciated the help from forum members wrt this issue.