Auto-dimming Rear View Mirror w/Homelink

I bought the Gentex GENK41A mirror off Ebay for $169 (I see it on Amazon also for $158 plus shipping). This is the same mirror I have in my 2004 Prius, with three garage door buttons and auto-dimming mirror, no compass or backup camera, athough versions with this are available at a higher price.

My 2010 Prius is the Prius III with navigation only.

Installation took a couple hours, but I went slow and steady, could have been faster and it was 100 degrees today.

It requires about $5 worth of parts (wire splices, connectors and wire). Removing the mirror was surprisingly easy, there is a tab underneath the mirror base that you release with a small flat screwdriver and it slips off. The new mirror slips over the button and is anchored with a small screw requiring a #20 torx screwdriver.

Next, I popped off the plastic cover for the sunglass holder and the domelights, just used my fingers. Remove the white wire harness from the dome light (there is a small tab in the back that releases it). Using a multimeter, identify the "always hot" wire (I believe it was the white wire top right looking up at the harness in its installed position). I used the wire splice connector that came with the mirror.

There are three wires that need to be attached, a ground, an accessory and an "always hot". I ran the ground and the accessory wire under the ceiling panel, down the side pillar and under the driver side dash. I attached the ground to a nut on the parking brake.

For the accessory (ie only on when the car is on) I removed the power port cover underneath the radio (it just pops out, I used a plastic pot scraper to avoid scratches) and pulled the white coupling off the power port. Surpringly, the black wire was the hot wire, but double check with the multimeter. Because I wanted to have that power port always on to charge my cell phone, I cut the power wire (which is only on when the car is on) and ran a wire to the previously identified "always hot" wire on the dome light as decribed above. Now I am able to keep my cell phone charged even when the car is "off" (in 6 years I've never drawn the battery down in my 2004 Prius using this method). I attached another wire to the accessory wire and ran that to the appropriate wire for the mirror using wire connectors and I attached the wires under the dash using plastic ties so they cannot be seen.

Works well, looks good, saved a lot of money.

 

How much of the dash/trim did you have to remove to run the wiring?

Thanks in advance,

Tom

 

Do you live in the Phoenix area? If so what would you charge to add the same mirror to the same car?

 

Can you tell me some information about the service facility that will be doing your installation in Tucson?

 

I agree. This is the first car I had with the autodimming mirror. Everytime someone is behind me at night I reach for the switch to change it to Night but lo and behold...there isn't any. A waste of money.

 

The issue with the mirror not dimming is due to the shadow from the rear spoiler falling on the mirror's sensor. I've not done a search for this yet on this site, but there must be a "fix" for this. I've played around with different mirror adjustments, and frankly, if I could turn the mirror upside down, where the sensor was on the top instead of the bottom, the mirror would work perfectly. Of course, there may be a more elegant solution to this issue that I haven't stumbled across yet. I've had these mirrors in other cars, and when they work, they work great. I will be tinting my windows this spring, so I think the issue will become moot...but in the meantime, I sure would like it to work more consistently.