STEP ONE: Disconnect the battery. You will be working with electricity. If your car is a 2003-2005, you already know where this is headed. You had to do the same thing with the radio. Well, I did...
*SPOILER ALERT*:
You will be wiring the positive wire to the ignition wire behind the radio. You can tap into another fused source that turns on when the car is in "ACC" mode, such as the cigarette lighter (although my car's lighter seems to be on constantly. Not sure if it just my car or the N body all together)
It is up to you where you get your 12+ constant from.
STEP TWO: Take your T20 screwdriver and unscrew the torx screw that holds the rear view mirror on to the windshield wedge.
STEP THREE: Slide the rear view mirror up so it detaches from the windshield.
You now have no rear view mirror in your car. If your car came equipped with map lights, disconnect the harness from the mirror. You MAY be able to use the positive and negative wires from that harness, but I believe it may keep the mirror on when the key is out. This is a "don't quote me" situation.
STEP FOUR: Look at your wiring harness. From center of the mirror, you will see pin 1. pin 7 will be the one that is closest to the driver's door. Each car has different colored wiring, so I cannot tell you what color goes to which. To be clear, you will be using pins 1, 2, 6, and 7. Pin 1 is 12+, Pin 2 is ground, Pin 6 is 12+ for the ambient temperature, and pin 7 is the ground.
IF You want the mirror to not be dim when your car is in reverse, you have to tap into your reverse lights. There should be a fuse under the hood that is for the reverse lights. If it's not there, then it's in the driver's side dash fuse panel. If not, it is recommended that you ground that wire. It will prevent the circuit from being open. The wire in question is pin 3.
For your curiousity, pins 4 and 5 are for your side view mirrors. Some cars also had auto dimming side view mirrors. We will be able to use that if we ever get someone to make us an autodimming mirror with turn signals. Until that day happens, it is a loss.
STEP FIVE: Start running wire to the wiring harness. It should be about 5 feet to get from the rear view mirror to the center console. You can ground where ever you want so long it's metal. I grounded near the kick panel to keep my ground as short as possible. Here is where the red and black wire will be handy. The red will be your positive, the black will be ground. Run all black wires like I did and you'll have to trace each wire every time you need to modify something. Also, if you have a loom or some other way to hide your wiring, right now is the time to utilize that method of hiding/protecting the wire.
It should be about 6 to 8 feet from the front of the car to the inside of the car. There is also a rubber grommet near the brake booster where you can run your wires into the cabin from inside of the hood. You will need to do this so you don't run the wires through the door jamb. Remember that you have to wire in the temperature sensor too. The good news is that you don't have to add it to a switched source.
STEP SIX: Remove your "A" pillar plastic cover. If you don't know what an "A" Pillar is, it is the metal between the door opening and the windshield. Inside the car, there is usually a piece of plastic that runs down diagonally that covers up the metal. A pull from the top will dislodge it from the car.
STEP SEVEN: Start tucking the wire in the "A" pillar from each direction, in other words, put the freshly wired harness on the back of the mirror and then put your fingers to lift down the cardboard that holds the headliner just enough to fit the wire and not have it exposed. This wire will lead to the "A" Pillar.
At the same time you will also have to tuck the ambient sensor in the kick panel and behind the dash as it goes up. The same will hold true for the 12+ wire, except you will run it down instead of up. When you run the 12+, you will want to tuck it under the crevice of the dash to get to the center console. If you're tapping into the fusebox in the dash, you're basically done.
STEP EIGHT: Remove radio by removing the ring around the ignition, and the trim around the radio and HVAC controls. They come off when you pry on them or put a screwdriver around the edges to pop off.
The radio has 3 8MM bolts that hold it into place. Take them off and the radio slides out.
STEP NINE: Locate the thick brown looking wire near the mess of wires in the dash. Mine personally was brown, but it can be another color in your car. It should be the thickest wire of all. Use a razor blade to peel off the plastic and expose some copper.
Afterwards, wrap or solder the positive from the mirror into that wire. It should be your ignition wire. Then seal it off and make sure there is no way it will make any contact with anything else.
STEP TEN: Reverse everything you did. This should be common sense and you should be reversing steps as you no longer work in the area. For example, you should put the "A" pillar plastic back when all the wires are nicely tucked. You should put the screw on the mirror when you will no longer be pulling it out of its wedge, etc.
Assuming you did the installation right, you should now be able to reconnect the battery, and place the car in the "ACC" position. This will now turn on your mirror as well. IF YOU HAVE A GRAND AM, THE MIRROR WILL NOT MATCH THE RED INTERIOR LIGHTS. This is AleroMod though, so for all the Alero guys, you're lucky to have green interior lights. It will match the STOCK radio read out and the gauge cluster.
There will be two buttons towards the center of the bottom of the mirror. One reads "COMP" and the other reads "TEMP". These are your compass and temperature buttons. When you press it, you will have a readout of your location and your local outside temperature respectively.
The temperature should be about 1 or 2 degrees off to what is being reported in your area. It's normal. It's not a wrong read out, but temperature readouts have numerous variables. The most important variable is location of the temperature sensor. On buildings that have the sign that read it out, more than likely it is somewhere where it gets a lot of wind. That will make it read differently. Likewise the heat of your car's surrounding will throw it off by a degree or 2.
BEFORE YOU GO OFF BRAGGING, THERE'S ONE MORE STEP!!!
Calibrating the compass:
These mirrors will more than likely be out of calibration. To understand that, you have to understand these mirrors work by programming them to a certain compass variance zone. They're preset from factory to be with zone 8. Most of us don't live in zone 8. I'm in DC so I live in zone 10.
Using my locality as an example, this is how you calibrate the compass...
STEP ONE: In an open parking lot, with the car on and started, press and hold the "comp" button until you see a number , usually "8" on the display.
STEP TWO: Using the map that will be linked below, look for your state. I live in Washington, DC so the zone is zone 10. I will press the "COMP" button until I see the number "10". If your state is split in 2 zones, choose the zone you are closest to.
For example, if you live in the state of North Carolina, Charlotte, NC will be in zone 9 but Raleigh, NC will be in zone 10.
STEP THREE: You now have to calibrate your mirror. Press the "COMP" button until the letter "C" shows up. You will more than likely see a number first, but if you keep holding it, the letter "C" will show up.
STEP FOUR: In the open parking lot, drive in small, tight circles, going no more than 5mph. The easiest and safest way to do this is to circle around a block of 4 parking spaces.
You will want to drive in circles 3 times.
Your mirror should now show the correct direction your car is pointed at.
Auto dimming will be a feature that will turn on on its own when obnoxious drivers are behind you. You should see the mirror turn green as a big SUV or a car with blinding lights approaches your rear end!