2012 Rearview Mirror Wiring has me Stumped

I finally have gotten around to trying to wire up the Homelink and Temperature in the 2012 rearview mirror I installed in my 2010 DC V6. The mirror has been installed with the backup camera and compass working great for a couple of months now.

Wiring up the Homelink was easy, but I can not get the mirror to recognize the temp signal. I followed the wiring diagrams in this thread.

I have verified a 0.0 ohm connection between the yellow wire on the old console connector to the mirror connector. I used my multimeter to look for any signal on the yellow wire and all I can tell is that it appears to be an AC signal (very limited digital multimeter). As far as I know the 2012 mirror is compatible with the AC signal output by the 2009+ system.

What am I missing???

 

No one can get the temp readout to work. If you figure it out let us know. I got nowhere at the dealership so the next move may be to contact Gentex.

 

Ugh, I did some more reading. I was under the impression that the only trucks that were having trouble were the 4cyl. Apparently there is some difference with the 2012+ wiring.

Extra annoying since I already got rid of my overhead console with temp/compass.

 

I did the same thing. Someone will figure it out. I went to the dealership and they told me the mirror should have came with a thermistor. I am not exactly sure what they are talking about. The ambient temp sensor is the same between model years. It must be how the signal is interpreted from the sensor to the overhead. The only thing I didn't check is if the A/C amplifier is different. I just don't know enough.

 

Not sure what the AC amplifier is doing on the console-equipped trucks, but it sounds like part of the temp display circuit is located outside of the console.

The mirror is completely self contained. It's temp display is driven by the thermistor behind the grille. It's very simple... at the lowest end of it's usable range, the resistance will be either zero or "open", and at the high end of it's scale it will read again zero or open, depending on whether the thermistor is a positive or negative type.

Anyways, the Gentex does not use an external AC amplifier, and connecting the one in the truck to the mirror could potentially damage the mirror. It is simply looking for a resistance reading, nothing more.

 

This certainly makes sense, but I can't find any info on what thermistor that mirror wants. I guess I need to try just wiring directly from the existing probe to the mirror. Can't hurt anyway.

 

That should do it.

Or...
http://www.ebay.com/itm/GENTEX-DONN...Parts_Accessories&hash=item45f6ad0796&vxp=mtr

 

I thought somebody had tried going directly from the sensor to the mirror in the other thread but I may be mistaken. It's worth a shot though.

 

Well in my frustrated stupor last night I never found the sensor anyway. Anyone know where that thing is located?

 

Post up diagrams if you can. I will pass them on to my dad. He's all sorts of techy savvy.

 

If I find some, I will. I am actually pretty handy with a wiring diagram myself. So I am looking for them. I think some guys who have been working on this in another thread have access to some of that info.

 

It's mounted right in front of the radiator about dead center.

 

Wow, don't know how I missed that.