Well my Challenger does not have the elec group with all the displays. I wanted a auto domming mirror so I solved the problem in one full sweep. I bought a mirror from a local salvage yard for $20.00. It is a Gentex with auto dim, compass and outside temp. It simply replaces the standard mirror and was easy to wire up. If you go this way you will also need the temp sensor that is located behind the grill on the donner truck. The one I got is from a late 90's to early 2000's Chevy pickup. Just don't get one with On Star as that one needs to be wired throught the computer to work, so I'm told.

The wire conections are:

Here is the low down on the connections to a Gentex mirror (with comp and temp) cut from a late model GM product. The connector
pin numbers are found on the wire incursion side of the mating connector.
GM wire harness color function
PIN 1 PINK POWER +12 volts
PIN 2 BK CHASSIS, GND
PIN 3 LT GRN BACKUP LIGHTS
PIN 4 GY TO AUTO DIM OUTSIDE MIRROR ( Don't use )
PIN 5 PINK TO AUTO DIM OUTSIDE MIRROR ( Don't use )
PIN 6 DR GRN/WT TEMP PROBE
PIN 7 BK/WT TEMP PROBE
Note: Pin 3 is to be connected to the backup lights to turn off the auto dim feature in reverse. If you intend not to use this
feature connect the LT GRN wire to chassis ground. If this pin is floating the auto dim will not work properly. Hope this helps.


This is the programming directions:

Gentex NVS Auto-Dimming Comp/Temp Mirror
* Fully Automatic electrochromic auto-dimming mirror
* Full Range Dimming - 75% - 6%
* Automatically disables dimming during daytime
* Digital compass with PathPoint™ continuous calibration software
* Outside temperature display
* Ice alert warning below 38° Fahrenheit
* Vacuum fluorescent display brightens and dims automatically
Auto-Dimming Switch Function
* Hold Temp switch for 15 seconds to disable Auto Dimming and Auto LED will go off. Repeat step to enable Auto Dimming and the Auto LED will come on.
Compass Switch Functions
* Push in Comp switch to turn Compass on/off.
Zone Variation
This compass must be set to compensate for the variation between true north and magnetic north. To set variation:
* Turn ignition on.
* Using the map below to find your geographic location, note the zone that you are in.
* To select Zone, push in the Comp switch for 3 seconds until the Zone selection comes up. Release, then toggle until correct zone is found and release switch. After 5 seconds of no switch activity, display will return to normal temperature reading.
Compass Calibration
This compass automatically calibrates itself while the vehicle is driven as your route takes you in complete circles. Therefore no calibration should be required, though it may take up to an hour. A quicker method is listed below. If the vehicle's compass headings become inaccurate, the compass can be manually calibrated by:
* Turn ignition on.
* Zone variation needs to be changed to use in different areas of the country.
* For a different Zone selection, push in the Comp switch for 3 seconds until the Zone selection comes up. Release, then toggle until correct zone is found and release switch.
* To re-calibrate, hold the Comp switch for 6 seconds until a "C" is displayed. Drive your vehicle in at least 3 circles, allowing 45 seconds to complete one circle.
Temperature Function
* Push in Temp switch to display outside temperature, and to toggle Temp on/off.
* Push Temp switch for 3 seconds until display blinks F° or C°. Release, then toggle Temp switch to select F° and C°. After 5 seconds of no switch activity, display will return to normal temperature reading.
Ice Feature
Display will indicate "ICE" to alert driver to potential driving hazard when temperatures are below 38° F.
WARNING
DO NOT LOCATE A CELLULAR ANTENNA WITHIN 24" OF THE MIRROR.