Adding mirror turn signals?

todd308 · October 17, 2020

So sadly while packing everything under the sun into the 2020 1500 mirrors it seems turn signals lost out......no idea why, cost cutting most likely.

That being said, has anyone tried to add turn signals to the factory mirrors? Seems like at least there's the capability for them as the optional tow mirrors have turn signals in them, but they do require a new door wiring harness so perhaps that would need to be added as well. It might also require programing as it says for the optional tow mirrors the BCM has to be reprogrammed, but it's hard to say if that's for turn signal function or something else.

Don't really need them, just thought it might be an interesting mod if it doesn't require giving a dealer $$$ to reprogram a BCM and the wiring hookups are there.

19gmcsierraat4 · October 18, 2020

I'm interested... Hopefully someone has some info on this.

TA^Guy · October 19, 2020

This is something I've been interested in since I test drove the new trucks last year. I would like the signal integrated with the work light on the back of the mirror but use separate amber LEDs in the housing. I would also like the signals on the mirror side which I miss from my 2015. On the highway I hit the signal to change lane, look in my mirror and wonder if they were actually on or not. The 'click' from the signal is so faint I can't hear it, and now there is no visual signal in the mirror so I never know if I tapped the stalk enough or not. Not to mention, I liked the signal on the side since I tow a 30' trailer and it helps others see when I'm signaling to change lanes.

No, I really don't want the tow mirrors. I think they are horrible looking and I don't need to mammoth things every day, but I must admit I do like all the features they offer.

Any insight if the harness for the signals are already there and functional would be very helpful.

todd308 · October 23, 2020

I emailed Boost on this since they have some mirror wiring harnesses and mirrors they do for the 2019+ Sierra's to see if they have any input on what is needed.

It sure seems like the small mirror caps would be a perfect platform to add turn signal LED strip lights to and a kit that does something like that would be right up their alley.

I'll post what I hear back.

aragrev7 · October 23, 2020

57 minutes ago, todd308 said:

I emailed Boost on this since they have some mirror wiring harnesses and mirrors they do for the 2019+ Sierra's to see if they have any input on what is needed.

It sure seems like the small mirror caps would be a perfect platform to add turn signal LED strip lights to and a kit that does something like that would be right up their alley.

I'll post what I hear back.

I’m in for that! I agree it’s missing on my AT4. Haven’t been without it since 2005 on my vehicles

todd308 · October 23, 2020

Unfortunately their only response was that they have no plans to offer anything, but would pass along the interest to the engineers. So I guess for those that read this give them an email and if there's enough interest maybe they'll make something. I had hoped they might have some info as to what is needed to do the upgrade but no luck there.

I still think a set of mirror caps that had plug in capability to add turn signals would be a good seller.

Edited October 23, 2020 by todd308

Vigilante375 · October 23, 2020

I looked at adding turn signal mirrors and found videos from the last gen truck where people would just plug in another truck trims mirrors and it would work. Because the wiring is already there and works with nothing other than plugging it in.

Yes I know the fog lamps have to be programmed in, which is stupid but oh well.

https://www.gmpartsclub.com/oem-parts/gm-exterior-mirror-covers-84328136?origin=pla&utm_term=&utm_campaign=Catalog+Smart+Shopping&utm_source=adwords&utm_medium=ppc&hsa_acc=1931327731&hsa_cam=9158758542&hsa_grp=87904691250&hsa_ad=414787673482&hsa_src=u&hsa_tgt=pla-293946777986&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gclid=CjwKCAjw_sn8BRBrEiwAnUGJDs4fQh5ViMQ2QUI2y-VeqvK0HsVD038KteXySXMYquGNM48VcniP9xoCMzIQAvD_BwE

Aren't these turn signal mirrors from the Trail Boss? I don't see why they wouldn't plug and play if the wiring is already there.

Hasn't that been found to be true for those wanting to add the factory bed camera?

Rob Mugs · October 24, 2020

2 hours ago, Vigilante375 said:

I looked at adding turn signal mirrors and found videos from the last gen truck where people would just plug in another truck trims mirrors and it would work. Because the wiring is already there and works with nothing other than plugging it in.

Yes I know the fog lamps have to be programmed in, which is stupid but oh well.

https://www.gmpartsclub.com/oem-parts/gm-exterior-mirror-covers-84328136?origin=pla&utm_term=&utm_campaign=Catalog+Smart+Shopping&utm_source=adwords&utm_medium=ppc&hsa_acc=1931327731&hsa_cam=9158758542&hsa_grp=87904691250&hsa_ad=414787673482&hsa_src=u&hsa_tgt=pla-293946777986&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gclid=CjwKCAjw_sn8BRBrEiwAnUGJDs4fQh5ViMQ2QUI2y-VeqvK0HsVD038KteXySXMYquGNM48VcniP9xoCMzIQAvD_BwE

Aren't these turn signal mirrors from the Trail Boss? I don't see why they wouldn't plug and play if the wiring is already there.

Hasn't that been found to be true for those wanting to add the factory bed camera?

Sure as heck looks like it. I bought a strangely optioned truck. Has every single option BUT the lane keep assist/old lady warning sensors/mirrors. Not sure why for the extra 800 bucks they skipped but could be lack of parts during the Rona?

That's not a bad price if they're plug and play

BluegrassMotorsport · October 24, 2020

3 hours ago, Vigilante375 said:

Aren't these turn signal mirrors from the Trail Boss? I don't see why they wouldn't plug and play if the wiring is already there.

Hasn't that been found to be true for those wanting to add the factory bed camera?

Those aren't turn signal mirrors although they look like they should be. I have them on my RST and I thought the same thing. Turns out they came with the safety package and they're essentially LED spotlights. Pretty darn bright but can only be used in Park. I haven't found a use for them yet but they're neat. You can turn them both on or each mirror individually.

Vigilante375 · October 24, 2020

12 hours ago, BluegrassMotorsport said:

Those aren't turn signal mirrors although they look like they should be. I have them on my RST and I thought the same thing. Turns out they came with the safety package and they're essentially LED spotlights. Pretty darn bright but can only be used in Park. I haven't found a use for them yet but they're neat. You can turn them both on or each mirror individually.

Well that's a bunch of crap. Glad to know what they do.

Wish that those would have been turn signals. Oh well.

TA^Guy · November 10, 2020

On 10/23/2020 at 3:14 PM, todd308 said:

It sure seems like the small mirror caps would be a perfect platform to add turn signal LED strip lights to and a kit that does something like that would be right up their alley.

I'll post what I hear back.

I'd rather have a replacement for the spot light that has spot light and turn signal in the same lens rather than a separate light in the mirror cap. Tempted to find a cheap used one on EBay to experiment with.

Edited November 11, 2020 by TA^Guy

todd308 · November 10, 2020

True that would be a very clean way to do it and honestly aside for another cost cutting step I can't see why they didn't include it.

The only thing that's been holding me back so far is the unknown of what is needed and the expense. Both if the new door wiring harness is needed which is required for the towing mirrors and/or if the ECM needs to be reprogrammed.

Juddmann · February 3, 2021

So i have a 2021 sierra with the spot lights on the front mirrors and from what im reading theres no work around just being used in park. I havent modded much since my 04 avalanche so Im sure a lot has changed since then. Seeing there isnt much use for the spot lights and more function with turn signals why not rewire the connection points. Pull the pin for the spot light on the mirror side of the harness and run that to the turn signal wire and tap off of that? Not sure how far that would be for each mirror or if there's a wire in the harness already. For a little bit of work and some wire its a cheap easy work around. There's a mod you can buy for the auto stop start switch that remembers the switches position but damn pricey. Maybe they will have a mod for the spot lights but still need to bypass park too lol. Signals sound way easier and cheaper.

BluegrassMotorsport · February 3, 2021

10 minutes ago, Juddmann said:

So i have a 2021 sierra with the spot lights on the front mirrors and from what im reading theres no work around just being used in park. I havent modded much since my 04 avalanche so Im sure a lot has changed since then. Seeing there isnt much use for the spot lights and more function with turn signals why not rewire the connection points. Pull the pin for the spot light on the mirror side of the harness and run that to the turn signal wire and tap off of that? Not sure how far that would be for each mirror or if there's a wire in the harness already. For a little bit of work and some wire its a cheap easy work around. There's a mod you can buy for the auto stop start switch that remembers the switches position but damn pricey. Maybe they will have a mod for the spot lights but still need to bypass park too lol. Signals sound way easier and cheaper.

Boost has a harness that will turn the spotlights on with the high beams. Not very pricey either and pretty easy to install. I don't know how bright they would be on the road at night. I've never tried them outside my driveway. But it could be a cool addition.

gemarsh · February 3, 2021

On 10/19/2020 at 1:16 PM, TA^Guy said:

This is something I've been interested in since I test drove the new trucks last year. I would like the signal integrated with the work light on the back of the mirror but use separate amber LEDs in the housing. I would also like the signals on the mirror side which I miss from my 2015. On the highway I hit the signal to change lane, look in my mirror and wonder if they were actually on or not. The 'click' from the signal is so faint I can't hear it, and now there is no visual signal in the mirror so I never know if I tapped the stalk enough or not. Not to mention, I liked the signal on the side since I tow a 30' trailer and it helps others see when I'm signaling to change lanes.

No, I really don't want the tow mirrors. I think they are horrible looking and I don't need to mammoth things every day, but I must admit I do like all the features they offer.

Any insight if the harness for the signals are already there and functional would be very helpful.

28 minutes ago, BluegrassMotorsport said:

Boost has a harness that will turn the spotlights on with the high beams. Not very pricey either and pretty easy to install. I don't know how bright they would be on the road at night. I've never tried them outside my driveway. But it could be a cool addition.

I have that kit. Really brightens the road ditches up on country roads. Kit maintains the oem functions of the switch when brights are off.