Description Reviews MINI made a lot of changes on the N18 Thermostat, so they had to make a wire harness that would go between the MINI Cooper thermostat and the main engine wire harness on certain year till the main engine wire harness could be changed to reflect the change in the thermostat. Look at your car and make sure you have the correct parts needed! Have any questions, give us a call. Harness Options: Harness 1: Build Date up to 07/12 Part Number 12-51-8-611-289 (the most common harness) Harness 2: Build Date 07/12-02/13 Part Number 12-51-8-614-952 1 Review 5 N18 Harness Posted by Bill melan on 24th Sep 2018 Awesome service!!!!