2018 Cadillac XTS ZCI Circuit Protected Vehicle Wiring 2018 Cadillac XTS wiring from Tekonsha. Product reviews from other XTS owners. Expert wiring advice with thousands of helpful questions and answers. The Tekonsha wiring harness was a bit difficult to install, as the clip-on connections are a somewhat bulky to fit in my Tesla Model 3's tight spaces. The good news is: they work as promised4.6/5(166)Category: WiringBrand: Tekonsha Cadillac XTS OE Wiring Harnesses & Stereo Adapters — CARiD We have you covered with top-notch wiring harnesses designed precisely for your Cadillac XTS by the most trustworthy brands in the industry. Cadillac XTS wire harnesses showcased on our digital shelves provide efficient, worry-free operation of many parts of the vehicle. Also, it makes installation a breeze.