How-To: A10 Inside RearView Auto Dimming Mirror Conversion (DD8)

mikejeep · January 25, 2019

I have a 2016 Silverado 1500 LT with the DL3 side mirror upgrade using pgamboa's harness. My existing inside mirror is the non-autodim OnStar model. I'd like to get autodim plus Homelink on the mirror.. I don't need OnStar. The Gentex GENK40A4 appears to do this.. but would it work in my scenario? And would the side mirror dim?

There's an eBay listing right now that says it's plug-and-play "as long as your vehicle currently has the factory 10 pin auto dim mirror without OnStar." That's not what I have, but curious if pgamboa's second custom harness would get me what I'm hoping for..?

-Mike

Edited January 25, 2019 by mikejeep

pgamboa · January 25, 2019

I have a 2016 Silverado 1500 LT with the DL3 side mirror upgrade using pgamboa's harness. My existing inside mirror is the non-autodim OnStar model. I'd like to get autodim plus Homelink on the mirror.. I don't need OnStar. The Gentex GENK40A4 appears to do this.. but would it work in my scenario? And would the side mirror dim?

There's an eBay listing right now that says it's plug-and-play "as long as your vehicle currently has the factory 10 pin auto dim mirror without OnStar." That's not what I have, but curious if pgamboa's second custom harness would get me what I'm hoping for..?

-Mike

Mike,

Considering the listing states that you must have an existing dimming mirror, and without onstar, I’m not sure if you can use this mirror. It states it comes with an adapter harness as well, so no telling what they are doing with this adapter.

My $75 harness will add the dimming feature to a normal dimming mirror, which will meet their requirements... but again, I am flying blind since I don’t know what the adapter harness does.

Sent from my iPhone using Tapatalk

mikejeep · January 28, 2019

On 1/25/2019 at 7:18 AM, pgamboa said:

Considering the listing states that you must have an existing dimming mirror, and without onstar, I’m not sure if you can use this mirror. It states it comes with an adapter harness as well, so no telling what they are doing with this adapter.

My $75 harness will add the dimming feature to a normal dimming mirror, which will meet their requirements... but again, I am flying blind since I don’t know what the adapter harness does.

Thanks Phil! I reached out to the seller and he replied back looking for more details about your harness, so I directed him to this thread and explained what my ultimate goal was. He did confirm that the presence of OnStar in my current setup and the lack of it on his mirror will not cause any problems. Will post an update for everyone's benefit if I hear anything.

-Mike

rjp869 · February 11, 2019

On 1/28/2019 at 12:18 PM, mikejeep said:

Thanks Phil! I reached out to the seller and he replied back looking for more details about your harness, so I directed him to this thread and explained what my ultimate goal was. He did confirm that the presence of OnStar in my current setup and the lack of it on his mirror will not cause any problems. Will post an update for everyone's benefit if I hear anything.

-Mike

Mike,

Figured I would not only get signed up on the forum (been on my to-do list for way too long!), but also figured it best to reply here so everyone can see this. After reviewing this thread, I can say for sure that the Homelink mirrors we sell will work and will be plug & play if you do the wiring mods per Phil's info on the previous posts. Now...keep in mind that to keep it plug & play, you'd have to be OK with the Homelink buttons only being operable when the ignition is on, as there is no constant hot wire in the existing 10 pin plug. But if you happen to want Homelink to be operable at all times, we could separate out the Homelink power wire & you would then just need to run it to a nearby constant hot source, such as the maplights, and tap into one of those for constant power to the Homelink buttons. We can also include in our harness the exterior dimming mirror control wires, as well as the reverse light wire too if desired. Please note that not all of the Homelink mirrors have the exterior dimming mirror control wires, but considering we stock over 500 new and used mirrors, it won't be a problem to get you whichever mirror you'd like. And to confirm what was mentioned in a previous post, there won't be any issues if you have an OnStar mirror and remove it...the mirror only serves the purpose of having the OnStar control buttons, so if you don't use OnStar, it won't cause any problems or error messages or anything like that. Hope this helps!

johnhankel · March 19, 2019

I got with Phil and purchased his mirror harness that had two wires for the 12 volts and the reverse circuit. I got my mirror put in tonight and got the wiring installed as well... Worked flawless and now have a dimming mirror... Don't hesitate to add this to your truck... FYI, the wire running to the junction box by the e-brake pedal is very tricky to get landed... No pictures, but there are plenty in the thread....

Thanks Phil!!!

Edited March 19, 2019 by johnhankel

mikejeep · March 28, 2019

I wanted to provide a follow-up post for everyone regarding my attempt at upgrading my the rearview mirror in my Silverado 1500 LT with the custom harness from @pgamboa and the Gentex mirror from @rjp869 -- it works great!! I now have Homelink buttons built into the mirror, and auto-dimming on all my mirrors (I had previously upgraded my side view mirrors with Phil's DL3 custom mirror upgrade).

Phil and Bob are both true professionals that we are fortunate to have in this community. Both of my transactions with Phil were very easy, with incredibly fast shipping and great post-purchase support when I didn't understand something. Bob was equally fantastic, with fast shipping and great service. When I tried this installation, it didn't work at first -- I assumed I had messed up some wires, but Bob thought it might be his custom connector on the mirror. I sent it back to him and he rebuilt the connector and shipped it back to me on the same day he received it! He even offered to reimburse the return shipping for me.

If anyone is considering this mirror upgrade, use Phil and Bob and you'll be in good hands!

-Mike

Macgyuver · April 15, 2019

looking at the PDF and the pin-out for the mirror. It shows the mirror needs pins 1, 2, 8, and 9 connected, 4 wires, to make auto dimming work? So if I have those 4 wires connected already I am good, or do I still need to run jumpers.

Jon Truland · February 17, 2020

I just found this topic but I've already ordered the Gentex 80a from another seller. I don't have the factory dimming mirror and would like to add a factory connector on the new mirror, rather than hard-wiring it somewhere. Does anyone know what part # the mirror side of the connector is and where I can buy one? Or if Bob or someone else makes a plug-and-play harness to do this?

Thanks

Jon

blueknight32 · May 22, 2021

On 8/27/2017 at 12:27 PM, x63581 said:

This is a awesome thread, I love doing things like this to vehicles but I have a 2009 Chevy Tahoe. Is there a similar mod like this for this model?

blueknight32 · May 22, 2021

Awesome Stuff thanks for all the info! unfortunately I have a 2009 Chevy Tahoe and things seem to be a little different. Is there a comparable tutorial on adding a auto darkening rear view mirror for a 2009 Tahoe some there?