Today in our 2016 Buick Lacrosse, we're going to take a look at and show you how to install the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector. Part number is 118497. Now, this wiring harness for your Lacrosse is going to give you your turn signals, it's going to give you your brake signals, it's going to give you running lights, it's going to be very effective for small… see more >