Hi Kent, thank you for reaching out. If the gear on your actuator does not align with the gear in the vehicle when the mounting holes are lined up, it usually means the actuator and blend door gears are out of sync. To fix issues with the actuator, gently rotate the blend door or actuator gear before bolting it in place, avoiding force to prevent damage. If manual alignment is not feasible, a 9V battery can be used to power the actuator and adjust its gear position. Following the installation process, it is crucial to perform a recalibration or reset of the HVAC system, often by removing and reinstalling the control fuse. If your 2014 GMC Terrain Denali is an AWD, with A/C Auto Electronic Controls (C68), this A/C actuator should work effectively for your vehicle. You can use the link below to place your order while the part is in stock. https://www.carparts.com/a-fs-c-actuator/ac-delco/ac1574254?cpcid=Q1BHRzQ4NTB8V3JpdHRlbiBJbnRlcmFjdGlvbiBUZWFtIC0gQ1NRQXwvYS1mcy1jLWFjdHVhdG9yL2FjLWRlbGNvL2FjMTU3NDI1NHwyMDI1MDYwNg== Hope this helps. Enjoy your shopping!

Hi Suzanne, I'm glad to assist you. No, you don't. This is plug-and-play. Click on the link below for direct ordering to take advantage of our ongoing discount and limited stocks. I hope this helps, and happy shopping. https://www.carparts.com/hvac-heater-blend-door-actuator/ac-delco/ac1574254?can=CPAE1047_CSQA_20230322

Hi Otis, I'm pleased to assist you. Yes, this part goes under the dashboard. Click on the link below to order while supplies last. You'll get a 30-day post-purchase price match guarantee with your order. I hope this helps. Enjoy shopping at Carparts.com! https://www.carparts.com/hvac-heater-blend-door-actuator/ac-delco/ac1574254?can=CPGG4850_20220526