I have a 2019 Silverado RST and I was able to swap out the mirrors and my current harness was a perfect match, my power adjust and defrost work as before but the outside lights do not work. Harnessdoctor.com is said to be working on a new harness to make them work. Installation was pretty straightforward. Believe it was 5 screws in the door panel and 4 bolt to remove the mirror. Took longer getting everything together than it did installing the mirrors.