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Compass/temp Onstar Mirror Install


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Posted

I just got finished installing a factory mirror that I bought from Travis (Trav 13) and I'm pretty happy. The install was really easy, with the exception of getting the wires through the fire wall. I didn't find a whole lot of details on installing one of these, so I figured I would do a quick write up.

 

To add this to 07 and up GM's, you will need to run 3 wires along with the temperature sensor. I bought a wiring kit off of ebay that included a universal 16 pin harness, the temp sensor and temp sensor harness.

 

To start, I removed the 3 wires needed from the universal 16 pin harness because the harness isn't needed. It's not a direct replacement obviously due to all of the onstar wiring that is required. The only advantages to buying the 16 pin harness from ebay was that the wires were already set up with the correct pins, so that they would plug into my factory harness. It came with the temp sensor/wiring and temp sensor harness as well, which was a plus.

 

MirrorInstall002.jpg">

 

Next I simply unplugged and removed my existing mirror. (Torx screw)

MirrorInstall001.jpg">

 

I then located the required connections for the factory 16 pin harness. You will need a small jewelers tool or screwdriver to raise the pin lock on the harness before you can plug in the new wires.

 

Pins 6 and 7 (Temp probe connections)

Pin 13 (+12 V switched ignition)

 

Once I had the pins in I used some electrical tape to join the 3 new wires to the existing wiring.

 

**There is no need to run a ground because it is already there in Pin 8**

 

MirrorInstall004.jpg">

 

Next I took the 3 new wires and ran them under the headliner. You do not need to remove the headliner. Just gently pull down on the edge and tuck the wires, moving towards the driver-side A pillar (or whatever it's called). There is a small plastic insert that just pops out on the A pillar to reveal a small bolt. Remove it and then gently pop the trim piece out.

MirrorInstall009.jpg">

 

Now run the wires down the pillar. It helps if you use some electrical tape to secure them to the existing wires located here. From here you can pop off the fuse access panel, located on the driver-side edge of the dash, to access the wires and finish pulling them through.

MirrorInstall005.jpg">

 

Now this was the hard part (for me)...trying to get the wires through the firewall. There is a large rubber grommet to the left of the brake pedal, with alot of wiring coming through. That rubber is tough to punch through and you have to be careful not to cut any existing wires. I used a long screwdriver to get through. Once I had a guide hole, I taped the 3 wires together and then to the screwdriver, and put it back through. I was then able to grab the wires in the engine compartment and pull them the rest of the way through. **It's a tight spot and tough to see, but you can see in the pic, the two purple wires and one red wire going through.**

MirrorInstall007.jpg">

 

The rest is a super easy. Take the red wire (power) and route it to the fuse box under the hood. Fuse # 50 (refer to owners manual) is for "Auxillary Climate Control (Ignition), Compass-Temperature Mirror." Hook up the power source here. Now you just have the 2 temp wires to deal with.

** I just left them hanging by the under hood fuse box for now.**

 

Next you need to mount the temp sensor and harness. It's recommended that it be mounted in the center of the vehicle and in front of the radiator. You need to find a spot below the radiator if possible and at least 8" off of the ground. Free flowing air that is away from major heat sources is what is desired here. I found a small tab on the edge of one of the bumper brackets to mount mine (see below pic). I then routed the 2 wires from the temp sensor harness along the bumper and up into the engine compartment to where my other 2 temp wires were waiting (the 2 wires run from the mirror with the power wire). Then join the temp sensor wires from the mirror with the temp sensor wires from the sensor with two high temperature butt splice connectors.

 

 

MirrorInstall010.jpg">

 

 

It was really simple to do and it's definately a great mod. I spent a little over two hours on this, but I went really slow and had hell getting the wires through the fire wall. Hope this helps.

 

MirrorInstall011.jpg">

 

**You may also need to refer to the owners manual for proper calibration of the compass feature.**

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Posted

What mirror did you have originally? I have the auto dimming/onstar mirror and would love to upgrade to the compass/temp mirror.

Posted

The mirror I had originally was just the basic manual on-star mirror. The mirror I upgraded to has the auto-dimming feature, but to be honest I don't know if it is functional yet. I guess I will have to wait unitl tonight to see if that feature works.

Posted

So after a brief search on the net, I figured out how to test the auto-dim feature. I covered the forward facing photo cell with a towell and after a few seconds the mirror began to dim. VERY NICE!

Posted

I guess this is my question, I have all the spots but 4 on that connector being used. Does that mean I already have the temp wires there? I couldn't really tell from your picture exactly which pins you put the new wires in, could you get a closer pic or tell me how you counted the locations of the pins?

 

Also, I was just looking over the vehicle build sheet for my truck and it says it was built with the inside rearview mirror with compass and temp, but it's not the mirror in the truck, I have the auto-dimming/onstar mirror? Maybe it's already wired for the other mirror?

Posted
I guess this is my question, I have all the spots but 4 on that connector being used. Does that mean I already have the temp wires there? I couldn't really tell from your picture exactly which pins you put the new wires in, could you get a closer pic or tell me how you counted the locations of the pins?

 

Also, I was just looking over the vehicle build sheet for my truck and it says it was built with the inside rearview mirror with compass and temp, but it's not the mirror in the truck, I have the auto-dimming/onstar mirror? Maybe it's already wired for the other mirror?

 

 

If you look at the back of the harness, where the wires are plugged in, you will see that they are numbered. One row of pins will have "1" on one corner and "8" on the other. The other row will have "9" on one corner and "16" on the other. Just count in between them. You may already have the power wire for the auto dim, but I doubt you have the wiring for the temperature sensor and the probe.

Posted
I guess this is my question, I have all the spots but 4 on that connector being used. Does that mean I already have the temp wires there? I couldn't really tell from your picture exactly which pins you put the new wires in, could you get a closer pic or tell me how you counted the locations of the pins?

 

Also, I was just looking over the vehicle build sheet for my truck and it says it was built with the inside rearview mirror with compass and temp, but it's not the mirror in the truck, I have the auto-dimming/onstar mirror? Maybe it's already wired for the other mirror?

 

 

If you look at the back of the harness, where the wires are plugged in, you will see that they are numbered. One row of pins will have "1" on one corner and "8" on the other. The other row will have "9" on one corner and "16" on the other. Just count in between them. You may already have the power wire for the auto dim, but I doubt you have the wiring for the temperature sensor and the probe.

 

 

Actually, I think I do. I looked up front and I have 2 temp sensors behind the grille. And I think I have wires in the locations needed for the temp sensor at the mirror. I'll double check in a bit. I'm guessing someone replaced the mirror for some reason cause it looks like I should be able to just plug the new one in.

 

Here's some crappy cell phone pics of the plug, looks all there to me?

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Posted

Looks like you should be set up for plug and play then. If you search around the net a bit, you can get the Comp/Temp mirror for around $50. :lol:

 

Something I forgot to add in my original post is that you have to calibrate the compass due to variations in magnetic and true north based on the zone you live in. Check out the owners manual for the how to. Keep that in mind if you swap out.

  • 8 months later...
Posted
So after a brief search on the net, I figured out how to test the auto-dim feature. I covered the forward facing photo cell with a towell and after a few seconds the mirror began to dim. VERY NICE!

 

Super write-up, Matt! :thumbs: I've just started my up-grade and I have a couple of questions: what gauge wire did you use and how long were the 3 pieces, did you splice the wires with the OEM pins to longer wires? If I missed the answers you may have already provided, then ... oops, sorry about that! But, thanks in advance for any help you can provide.

 

Mark

  • 2 weeks later...
Posted
Very nice write up man! Now come do it to mine

 

 

I did this back in Feb, and it's stupid easy to do. Maybe if you make me a pretty sig like yours I will drive to LA and hook you up. :lol:

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