How to add an Auto Dimming Mirror
Install an Auto-Dimming Mirror Yourself
An auto-dimming mirror eliminates the need to flip the lever at the bottom of your rear view mirror to eliminate glare. A traditional mirror reduces glare by changing the angle of the mirror to reflect a portion of the headliner in the mirror image.
How an auto-dimming mirror works
An auto-dimming mirror is built with a light sensor and two layers of glass that surround a layer of electrochromic gel. When the sensor detects light from vehicle headlights behind you, the circuitry sends an electric current into the gel causing it to dim. The amount of power and the level of dimming is directly proportional to the level of glare from the headlights entering the mirror.
Advantages of an auto-dimming mirror
• Minimizes the headlight glare from vehicles behind you for improved nighttime driving safety
• Mirror dims automatically as glare hits it
Which mirror to buy
Gentex is popular aftermarket brands. They made four models, starting at $125 for # ADVGEN2A a basic unit, then $230 for ADVGEN20A with a built in compass, ADVGEN40A4 $260 with HomeLink garage door opener buttons and ADVGEN45AB5 $340 for HomeLink and a compass. Purchase the mirror from Voxx Electronics or shop online for a cheaper price.
The three most popular models of auto dimming mirrors by Gentex
How to install the mirror in your car or truck
These mirrors require two wires; power and ground. My advice is to buy a short subscription to alldatadiy.com or eautorepair.net to download the diagrams to remove the headliner and the driver’s side A-pillar trim, as well as the fuse box layout.
This is an example of the removal diagrams for a 2014 Chevrolet Malibu using Alldatadiy.com
Removing the A-pillar trim is not difficult if you have the diagram. You just need to know where the clips are. It just snaps in place. The a same is true with the headliner. Here are the steps
• Remove your current mirror. Using a hex wrench. loosed the set screw holding it in place. Slide it up and off the windshield mount
• Remove the A-pillar trim on the driver’s side
Add-a-fuse adapter
• Unclip the headliner, starting at the A-pillar and over to the mirror
• Run a cable from the under dash fuse box up through the A-pillar and tuck it behind the headliner
• Connect the new cable to the auto-dimming mirror and mount it to the windshield mount. Tighten with hex wrench
• Use an Add-a-fuse adapter to an switched existing fuse and crimp the power wire to the crimp connector. Connect the ground wire to any existing ground point under the dash
• Reconnect pillar trim and headliner
©, 2020 Rick Muscoplat