Discussion Starter · #1 ·
Last weekend I had a few minutes and thought I would connect my Progeny 2 brake controller. I connected the supposedly correct adapter harness to the trailer connector inside the kick panel by the steering wheel. I called Tekonsha last week to verify that the 3035 adapter was the correct one. I connected the other end to my controller. I should have immediately seen a "nc" for no connection on the display. It was dead as a doornail. I unplugged the identical controller from my Denali and it too was dead in the RRS. I plugged the new unit into the Denali and it worked fine. I thought I had a dead trailer harness and tried looking at all the fuses in the passenger glovebox and the rear cargo area. (The manual's chart of the fuses doesn't look anything like the fuse panel by the way. We should get an accurate chart for future use). I made an appointment for this morning with the dealer near my home for to diagnose a dead trailer connector. I decided to test the circuitry this morning before bringing it in. With a voltmeter I was able to get 12 volts in the line that was supposed to activate the trailer brakes. With an ohmmeter and voltmeter, I was able to find the correct wires and moved them to the correct pin location in the adapter harness (after a couple of hours and a broken back. You have to lie upside down on the floor with a voltmeter and press on the brake pedal to figure this out. There are a lot of combinations and permutations). I was lucky the hot did not go to ground and blow a RRS fuse (since the is no fuse chart available) or destroy my new $129 brake controller which would have happened if hot and ground are reversed going to the controller. The RRS trailer connector has 5 wires but only 4 are needed. There is a red retaining tab in the adapter harness that once removed, will allow the terminals to come out with a sharp instrument (it helps to be a dentist). The harness pin locations are correct (I verified that with pictures online. So, either my RRS was wired incorrectly or the new RRS are wired differently from Range Rovers in the past and Tekonsha's adapter infor for the 2014 is wrong. If you are going to connect a Tekonsha brake controller, I would connect the harness and check the blue wire. If this is hot, change the terminals to the following pin locations. Sorry about being so verbose, but I thought this was pretty important. Hopefully you can make sense of the following chart.