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Adding turn signals to 2015+ HD tow mirrors


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Hi Everyone,

 

I recently picked up a set of the 2015+ HD DQS power folding tow mirrors. For those that aren't familiar with them, you can see them here: http://www.gm-trucks.com/forums/topic/163141-new-hd-mirrors/?p=1482048

 

Once getting them, the only thing I thought was missing from them was using the clearance lamps on the front of them as both running lights and turn signals. Unfortunately, from the factory, GM didn't do this for me. So, I set out to correct that.

 

The first thing that I thought about was how this could be done with an XOR circuit. Trying not to be too technical, an XOR circuit accepts two inputs, and have a single output. When either input is high, then the output is high. When either input is low or both inputs are high, then the output is low. This type of circuit would allow the clearance lamps to operate as both, with an inverted turn signal when the parking lamps were on. I scratched out a quick schematic here:

 

post-133565-0-05540100-1419380899_thumb.jpg

 

All this requires is a pair of single-pole, dual-throw automotive relays (the ones with 87a terminals on the bottom) and some wire. With +12V, ground, parking lamp input and turn signal input, this should work.

 

 

...But, I'm not the type to leave well enough alone, so I thought I'd come up with something smaller, and wanted to step into the digital age. So, I got to work.

 

First up, I came up with a schematic:

 

Tow mirror Led controller 1

 

 

And then designed a circuit board to go along with it:

 

Tow mirror Led controller 2

 

 

Once I was happy with that, I send the design out to a fab house to have boards made up. Here are the results:

 

Tow mirror Led controller 4

 

Did I mention it was small? It's roughly .65" tall and .95" wide. Next up, it was time to solder all the discreet components to the board:

 

Tow mirror Led controller 7

 

This microcontroller uses an Atmel microprocessor and accepts parking lamp and turn signal inputs. The output applies power to the LED clearance lamps on the front of the tow mirrors. I can pulse-width modulate the power to the LED clearance lamps, so that I can define the brightness of the LEDs. But, the best part about this controller is that it's fully programmable. So, if I want, I can set it up as an XOR circuit, or I can get a little more creative.

 

next up, I added some wiring and started testing:

 

post-133565-0-18437800-1420520648_thumb.jpg

 

And finally, after getting a pair of these hand soldered and programmed, I decided that I really didn't want to cut up the wiring harness on my truck. So, I sourced connectors and pins for the factory connectors on the mirrors. The results?

 

post-133565-0-07517400-1420520653_thumb.jpg

 

Plug and play tow mirror LED controllers.

It's too bad it's sub-ten-degrees outside right now, because I really want to get these installed.

 

As for how they work? Here is a video I uploaded to Youtube of how they operate:

 

 

 

I apologize for the low volume audio output;

The video explains how they work, but it's summed up like this:

 

When the parking lamp input is off, the clearance lamp operates with full brightness with the turn signal input. It basically flashes as the turn signal input is applied to it.

 

When the larking lamp input is on, the clearance lamps normally operate at full brightness. the controller does this until it starts to receive turn signal input. When that happens, the controller dims the clearance lamps when then turn signal is off and sets it to full power when the turn signal input is on. After a second without turn signal input, the clearance lamps fade back up to full brightness.

 

Overall, I'm happy with how these turned out, and am awaiting a day that's not unbearably cold so that I can install them. I'd be happy to answer any questions anyone has about them.

 

[Edited because the board ate my attachments!]

post-133565-0-05540100-1419380899_thumb.jpg

post-133565-0-18437800-1420520648_thumb.jpg

post-133565-0-07517400-1420520653_thumb.jpg

post-133565-0-18437800-1420520648_thumb.jpg

post-133565-0-07517400-1420520653_thumb.jpg

post-133565-0-05540100-1419380899_thumb.jpg

post-133565-0-18437800-1420520648_thumb.jpg

post-133565-0-07517400-1420520653_thumb.jpg

Edited by phydiux
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I get my mirrors on Wednesday, if you could make a set of these for me and mail them to me (I'll pay of course) then I would be glad to test them out :driving:

 

 

But next question I have, where did the input for the turn signal come from if they are now completely PNP? Did you just pull turn signal power from the turn signal that faces the rear of the vehicle? The one that is in the actual mirror. Also for those of us without the wiring from the factory for the amber running lights on the mirrors, we would still have to run a wire to our running lights, correct? (Not a problem for me as I have a switch in cab to turn the Amber RUNNING lights themselves off in my headlights without affecting any other lights in there.

Edited by Mike1220
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Very impressive! It seems like you know what you are doing when it comes to circuit design! You might be able to help us figure out how GM is driving the LED DRL's in our trucks. I think it might be something similar as I remember seeing a small circuit board inside the headlight housing.

 

 

Sent from my iPhone using Tapatalk

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Thanks everyone. I didn't have any plans to sell them, but it looks like everyone seems to want them. If I did have a batch of them made, I can let everyone know in this thread. They would almost certainly not include the plug and play harness because the connectors and terminals were very time consuming and hand crimping just 66 pins for both sides was not fun at all.

But next question I have, where did the input for the turn signal come from if they are now completely PNP? Did you just pull turn signal power from the turn signal that faces the rear of the vehicle? The one that is in the actual mirror. Also for those of us without the wiring from the factory for the amber running lights on the mirrors, we would still have to run a wire to our running lights, correct? (Not a problem for me as I have a switch in cab to turn the Amber RUNNING lights themselves off in my headlights without affecting any other lights in there.

 

Yep, the turn signal input is sourced from the same input used for the rear facing turn signal in the mirror. The rearward facing signal still works, I just spliced into it in the jumper harness I made so that the microcontroller can tell when they're on.

 

And yes, you still have to update your truck to source the parking lamp input in order for the parking lamp input to be operable. It sounds like you've already got that covered on your truck. On my truck, I have to make a reversible modification to unplug the puddle lamps from the BCM and connect it to a park lamp supply voltage. There's an open park lamp supply voltage terminal on the passenger fuse block, connector X1, pin 15. I'm using a small female spade terminal connector to connect to that.

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Thanks everyone. I didn't have any plans to sell them, but it looks like everyone seems to want them. If I did have a batch of them made, I can let everyone know in this thread. They would almost certainly not include the plug and play harness because the connectors and terminals were very time consuming and hand crimping just 66 pins for both sides was not fun at all.

 

 

 

Yep, the turn signal input is sourced from the same input used for the rear facing turn signal in the mirror. The rearward facing signal still works, I just spliced into it in the jumper harness I made so that the microcontroller can tell when they're on.

 

And yes, you still have to update your truck to source the parking lamp input in order for the parking lamp input to be operable. It sounds like you've already got that covered on your truck. On my truck, I have to make a reversible modification to unplug the puddle lamps from the BCM and connect it to a park lamp supply voltage. There's an open park lamp supply voltage terminal on the passenger fuse block, connector X1, pin 15. I'm using a small female spade terminal connector to connect to that.

 

But PNP is so much nicer [emoji106] you could totally just make me a set. Lol Edited by Mike1220
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For a set of these boards plus all the materials needed to make this PNP set up like you did, mind telling us about how much it would cost? I'm really curious about how much time and money would need to be put into making a set of these if I get to make a set.

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For the three I made (I made one to prototype and develop software for and two for the truck) I ended up spending under $75 and a weekend day, plus a few hours after work during the week to make the schematic and layout the board.

 

Cost also depends on the tools you have; I already had a programmer, crimp tool that worked well enough and soldering iron small enough.

 

Making even a small run would reduce cost a bit, PNP harness aside. I spent more time on that part than I spent on anything else for this project. It would be so much easier to cut the tow mirror's harness and that wouldn't affect the harness on the truck. The controller is about the same width as the connector on the mirror, so it should fit through the hole in the door that the harness goes through, too.

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For the three I made (I made one to prototype and develop software for and two for the truck) I ended up spending under $75 and a weekend day, plus a few hours after work during the week to make the schematic and layout the board.

 

Cost also depends on the tools you have; I already had a programmer, crimp tool that worked well enough and soldering iron small enough.

 

Making even a small run would reduce cost a bit, PNP harness aside. I spent more time on that part than I spent on anything else for this project. It would be so much easier to cut the tow mirror's harness and that wouldn't affect the harness on the truck. The controller is about the same width as the connector on the mirror, so it should fit through the hole in the door that the harness goes through, too.

What about for those of us who don't have a programmer or solder iron? I could get a soldering iron from a local auto parts store or hardware store. But not sure on the programmer or how much both of those would increase total cost.

 

What do you mean making a small run? Sorry, just trying to understand all possibilities with this project.

 

Also is the $75 for the PNP version that you made?

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Great job; very innovative!

Yes, I'd be in the market if you decide to sell even the board ...and source the components.


Great job; very innovative!

Yes, I'd be in the market if you decide to sell even the board ...and source the components.

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