Troubleshooting 2013 Jeep Wrangler Unlimited Wiring Issue with Curt 4-Way Harness  

This year Ive ordered the necessary parts from etrailer to install a 7-way harness and brake controller on my Jeep. Everything has been great, except for an odd glitch occurring after installation on my 2013 Jeep Wrangler Unlimited Sahara Auto. When I initially bought my used Wrangler, I noticed that it had a previously installed 4-WAY CURT Custom Wiring Harness. I was able to identify it as CURT brand since its identifying brand sticker was still attached to its wiring. Since that harness was already installed and I needed a 7-way, I chose to order from ETRAILER.COM the following parts: ETBC7 Universal Installation Kit and 90195 Teknosha Prodigy P3 Brake Controller. After I finished the install, I was pleased to see the brake controller working perfectly, however, my turn signals, running lights, and brake lights did NOT work. Since the brake controller portion of my install was working, I suspected that the previous owners install of the CURT 4-way was faulty. I confirmed my suspicion with a circuit tester before then opening the left tail light to reveal the T portion of the CURT 4-way harness. I saw that the T portion of the CURT 4-way harness had been unattached and was just resting in the tail light housing. I plugged the old 4-way harness back into the tail light wiring which then restored all 4-way tailer functions EXCEPT that reattaching the harness caused the left turn signal of my jeep and trailer NOT to work. I uninstalled the 4-way harness, assuming this was why the previous owner had uninstalled it, and I then ordered a brand new CURT custom wiring harness part number: 55124 as a replacement. When I installed the newly ordered CURT custom wiring harness everything worked perfectly, AT FIRST. After hauling a travel trailer 2 hours away and camping with no problems, I later ran into an odd problem after my camping trip when I hitched up to go home. After hitching up and plugging in, I started my jeep ignition to pull away and was instantly confronted with an engine light. I used a code reader that I keep handy in my jeep to see that the engine code thrown is B1644 REAR LEFT TURN CONTROL CIRCUIT HIGH. Fortunately, all trailer functions continued to work and got me home safely despite the code. However, Im afraid Im going to eventually wind up with a second harness that disables my left turn signal, as the one I replaced also had. When I got home and unhooked everything from the trailer, I attempted to clear the code from my vehicle, but the code returned almost instantly. Im sure if I uninstall the 4-way, things will probably return to normal, but I need to get this trailer wiring to work consistently and remain in place. What should I do as next steps to determine why the first 4-way harness disabled my left turn signal, and why the second 4-way harness is causing my jeep to throw a code of B1644 REAR LEFT TURN CONTROL CIRCUIT HIGH? With a booked up summer of camping, I really appreciate any help I can get resolving this problem ASAP??? Thanks!

asked by: Aaron M