To find the correct fuse:
1. Consult your owner's manual: Look for the fuse box diagrams. These diagrams will usually show the fuse assignments, including the one for the power mirrors. It might be listed as "Power Mirrors," "Mirrors," or something similar. It may not specify left or right individually, but often they share a fuse.
2. Locate the fuse box: Your DTS will have at least one fuse box, usually under the hood and possibly another inside the car (often in the glove box or under the dash).
3. Check the fuse: Once you've identified the correct fuse, visually inspect it for a blown filament (a broken wire inside the fuse).
Important Note: If you're not comfortable working with car electrical systems, it's best to take your vehicle to a qualified mechanic or auto electrician. Incorrectly replacing a fuse could cause further damage.