GENK40A Auto Dimming Rear View Mirror

It was incredibly easy to install -- took me about an hour, and most of that time was spent testing the car's wiring harness to find constant-12V, switched-12V, and ground wires to tap into. (Get yourself a good Digital Volt-Ohm Meter if you don't already have one!) It does exactly what I wanted it to do -- no compass or temperature display, which I didn't want since I already have both of those built-in to my car. But it DOES have the Homelink buttons so I don't have to carry around a separate garage-door opener anymore (yay!). The Homelink setup-instructions are pretty clear, too -- you'll need your current garage-door opener, and depending on the type of garage-door opener you have, you might need a ladder to climb up and press a "train" button on the garage-door motor itself. (Having a second person help you with this is not a bad idea -- he/she can press the "train" button while you're in the car operating the Homelink button you're programming. Took me all of 2 minutes to train the Homelink buttons to work with my garage door with the help of my girlfriend. Just make sure you're parked in a place where the door(s) won't come down on your car accidentally while you're training the Homelink button(s). And, supposedly, if you have the right system, you can train one of your unused Homelink buttons (there are three of them) to turn on-and-off lights inside the house! (My system doesn't do this, so I can't verify that personally.) The auto-dimming feature works *wonderfully*. No more having to flip my mirror manually -- this thing auto-adjusts the dimming depending on how bright the lights are behind you (goes from a little dimming to a LOT of dimming as the person gets closer to you), and it does so quite quickly so there's never a problem with glare ever. I highly recommend buying this mirror if you want an auto-dimming mirror that has the Homelink buttons on it, but you don't want the temperature or compass displayed in the upper-right corner of the mirror.

Came with no wiring instructions. Three wires. Ground. Black. Black with white stripe. One needs battery. One needs accessory. Hope I got it right. Mirror has four wires. Harness turns it into three wires. Wonder what that other wire does? Didn't realize it wasn't brand new. Probably wouldn't have paid as much for a pre-touched mirror. No idea what adventures it's been on.

This rear view mirror with auto dim and homelink is essentially identical to OEM mirrors in high quality cars. I think Gentex provides mirrors to the automakers as it looks identical to the one in my Subaru. Works great, simple to install and program. I took it to a stereo shop to run the wiring because i was unsure about messing with the headliner in a brand new nissan. Highly recommended if you want one.

I'd give this 5 stars if the "after market cable" provided was labeled (or wiring instructions were included) because this mirror/homelink product is excellent. It's in and working as advertised. That's the good news. The bad news is the installation was a lot longer and harder than the "1 hour" other reviewers indicated. I'm a biomedical engineer who actually installed X-Ray machines in hospitals so I know my way around a tool box. Here are some installation hints that may help future buyers install this excellent product: 1. The cable came with 2 different power wires (at least I think they were both power). One wire was solid black and the other was black with a white stripe and the ground wire with a spade lug. I reached out the seller and asked how to connect the 2 power wires. They couldn't remember. I did much research and the consensus of the group was to connect the power wire a ignition switched power source. I connected both wires to a switched power source. I turned on the ignition (with fire extinguisher in my hand) and the Mirror powered up and programmed perfectly. It continued to work after switching the ignition off and on. Yeah! 2. The other tip is: figure out what type of fuses your car uses and buy an "add a fuse" kit from Amazon for your fuse type. My Hyundai uses micro2 fuses so I ordered the correct "add a fuse kit" (pictured below). With THAT said, my Hyundai had tons of "spare" fuses and several fuses for features not included in my car (like power sun roof) but almost all of them were 24 hour power or hot with the ignition switch off. Only 3 unused fuse positions were switched power. 3. Finally a note about the "add a fuse"; be sure to check which leg is hot in your car's used box and which leg on the "add a fuse" if connected to your output wire. Otherwise you will end up not going through your "add a fuse" fuse but connecting your power wire directly to the fuse block. Not good. GENTEX GENK40A Auto Dimming Rear View Mirror

Plug type differs from 2005 Prius. This mirror has two teeth and one row of pins. 2005 Prius has one detent and two rows of pin sockets.

This mirror is awesome! No more garage door openers hanging off the visor, no more glaring headlights from behind. It was a breeze to install and it came with almost everything you need. I used two add-a-circuit devices and went straight into the fuse panel. My fuse panel uses ATM fuses so I had to purchase two five amp ATM fuses and had to use a few plastic tie raps but that was it. I highly recommend this product and don't be afraid of the install. It only took me an hour and that was from when I started pulling the trim to opening and closing the garage door.

I had hoped to have this style mirror for the Prius Prime that I just purchased, but it wasn't an option for the XLE (middle) model that I ended up buying. Dealership purchase and install of this style mirror would have been $1,000 or so, so I found the GENK40A with the hope it would fit. Turns out the installation was relatively straight-forward and it works absolutely perfectly. To install, I removed the ceiling cover and stock rearview mirror, installed the new mirror (easy). Importantly, I needed to carve out part of the mirror cover with a Dremel tool in to allow the GENK40A to have enough upward movement so that I had appropriate line-of-sight out the back window. (If you're really tall, it might be a problem to get enough vertical clearance.) I then ran the GENK40A wire along the left side moulding (taking care to stay behind the airbag), and down to the fusebox under the left-side dashboard, where I connected the wires to the fuse for the 12V outlet. Getting the HomeLink to connect with my fairly old garage door opener took a number of tries, but it eventually worked. Couldn't be happier!

I ordered the Gentex GENK40A and it is described with compass and temp but the mirror I received had neither. I will be calling for a return on Monday. Product not as described.

Installed in 2014 Dodge Grand Caravan by IASITY SOUND in Lethbridge, Alberta, Canada at a very reasonable cost. Programmed by owner. Works perfectly. An absolutely superb solution. Highly recommended.

Did not receive wire cover as advertised

Come with installation instructions. I was able to patch it to the sunroof power supply very easily. Works great!! Comes with Mito Harness.