Drivers side mirror won't go down

So I am posting this early without a year but I have seen this before on the TQ/QF Optima as well - it's a known disease with Hyundai/Kia equally. The mirrors use a plastic gearbox where they use a plastic gear where the failure is critical and if it runs for hours trying to close it, will drain the battery and shorten it's life. If both are affected I'd start with the fuse and check the wiring, but if the other is fine it's the mirror.

The cover is above the door card and comes off by hand for me - probably on mirror #3 with this Optima for the passenger and it will be on #2 with the driver side one, Look for a triangle cover. Without the year I can't find it but search "Hyundai Santa Fe [bad mirror] power mirror [model year]". You will need to match the trim level but BSD cars make that easy: they have a light on the mirror non ADAS cars lack and most are now including more ADAS features to get IIHS Top Safety pick awards. You can use your VIN as well: https://hyundai.oempartsonline.com/

Cover location (bolts are 10mm, deep socket is required):

CAUTION: ADAS CARS MIGHT NEED TO BE RECALIBRATED. OEM mirrors will allegedly self calibrate but my bumper sensor is bad and I can't cal that as I don't own the right tool and I'm not spending $1k+ on a scanner for a 100k mile Kia with a Theta II, so I can't test that. Aftermarket ones need to be calibrated every time. I'd rather swap the bad mirror, aftermarket passenger and put a used bumper sensor in, and then pay a guy $50-100 under the table with the scanner to do it in front of me, or take it to a shop who does cheap recalibrations.