Review on GENTEX GENK40A Auto Dimming Rear View Mirror: Enhance Your Driving Visibility by Jonathan Yang

I would give this 5 stars if the included 'After Sale Cable' was labeled (or included wiring instructions) because this Homelink mirror/product is excellent. It works and works as advertised. That's good news. The bad news is that the installation was much longer and more difficult than the '1 hour' that other reviewers quoted. I'm a biomedical engineer who has actually installed X-ray machines in hospitals, so I know how to use the toolbox. Here are some installation tips that may help future buyers install this excellent product: 1. The cable came with two different power cords (at least I think they are both power cords). One wire was solid black and the other was black with a white stripe and a ground wire with a spade lug. I contacted the seller and asked how to connect the 2 power wires. They couldn't remember. I did a lot of research and the group agreed to connect a power cable to a power source with an ignition switch. I connected both wires to a switching power supply. I turned on the ignition (extinguisher in hand) and turned on the mirror and programmed it perfectly. It continued to work after turning the ignition off and on. Yes! 2. Another tip, find out what type of fuse your car uses and purchase a fuse-adding kit for your fuse type from Revain. My Hyundai uses Micro2 fuses, so I ordered the correct "fuse set" (see image below). That being said my Hyundai had an abundance of "spare" fuses and a few fuses for functions not included in my car (like the power roof) but almost all of them worked 24 hours or were hot with the ignition off. Only 3 unused fuse positions were de-energized.3. Finally, a note on "Add a backup"; Be sure to check which foot in your car's used box is hot and which foot says "add a fuse" when connected to your output wire. Otherwise, don't use the "Add Fuse" fuse, instead connect the power cord directly to the fuse box. Not good. GENTEX GENK40A Auto dimming rearview mirror