20/20 Rearview

Every wanted one of those mirrors that dims automatically, has a compass, or can tell you what the outside temperature is? You can get it all in one package and get map lights to boot with a mirror from CIPA (Part #36500) and about 2 hours of your time. If this interests you, please read on through the installation. The installation is for a 1990 model 454SS.


Here is the mirror in an exploded view. See below for descriptions.

1) Mirror assembly (compass pod attached to mounting bracket)

2) Power wire harness

3) Wire tap (power connector)

4) Temperature sensor

5) Temperature sensor wire harness

6) Wire tie

7) Operation card (not pictured) for glove box

8) Replacement wedge button for windshield


  • Step 1: Start off by disconnecting the negative battery cable to avoid shorting of any components. Then remove the old mirror using a #20 Torx. Loosen the screw in the pictures and slide the mirror up towards the headliner; it should come off very easy. Using a lot of force can break the mirror or windshield, be careful.
  • Step 2: Sliding the new mirror in place I noticed a problem. The new mirror fits loose on the existing button. From here you have two options.
    • 1) Carefully remove the factory button and mount the new button supplied with the kit. This requires a run to the store for a new mirror mount adhesive kit.
    • 2) If you don't want to risk removing the button, do what I did. Cut a 1" long piece of 3/8" fuel hose and them cut 1/3 chuck out length-wise. Put this piece between the mirror and the button. Then tighten the screw with the #20 Torx. The mirror is then very stable and cannot be removed.

  • Step 3: Mount the temperature sensor near the front of the truck as far away from heat source as possible. The temperature reading will be more accurate if the engine heat does not interfere. I chose to mount on the driver's side bumper bracket by the wheel well (see picture). It ends up behind the driver's side fog lamp and towards the middle of the truck (since the light is a heat source). The reading from the unit will be more accurate when the truck is moving, sitting still the road temperatures can affect the reading. Run the wire harness, following the light flexible conduit, back up to the firewall on the driver side. Being careful not to damage the connector pins, run through the firewall using and existing hole or make a new one.

  • Step 4: Remove the driver's side sun visor. This will allow the headliner to drop down enough to get the wires above it. Now carefully pull out the driver's side A-pillar cover. To do this, remove the speaker cover and pull straight out on the A-pillar cover. The bottom of the pillar cover uses push-style locking pins like other dash components. The upper section of the A-pillar has compressed locking tabs. Tabs (3" long) from the cover slide into fixed pressure locking bars with spikes. Be very careful with these, I broke one. They pull straight down, best if a small screw driver can be used to pry open the locking bar from the outer side of the cover. Once the pillar cover is sitting out enough, run the power wire down and the temperature sensor wire up.
  • Step 5: Close the A-pillar in reverse order from Step 4. The wires are now hidden from view. Now slide the temperature sensor pins into the 7-pin connector using pins #4 and #5 (only if installing the same model, check instructions), polarity does not matter. Plug the connector into the back of the mirror and re-install the sun visor. The wires are now completely out of sight.
  • Step 6: Land the ground wire under the dash onto a suitable ground. Connect the power wire to an ignition controlled power source. If you do not connect it to an ignition controller source it will stay power up all the time and can run your battery down. The kit supplied a clamp-on connector that clamps over the power wire and accept a spade style connect (on wire harness) to plug into it. This allows the connection without cutting any wires, cool.
  • Step 7: Reconnect the negative battery cable and check the system components to verify they work. This is what you should see. Yes, the mirror temperature reading can be displayed in Fahrenheit and Celsius (for our Canadian members).

  • Step 8: Set the compass zone number according to the zone map that best fits your location from the installation instructions. The calibration of the compass is supposed to be automatic while you drive. To manually calibrate the unit, enter the calibration mode (see actual instructions) and drive around 2 or 3 small circles. They say to do this slow, so no full throttle spinning action (darn). Once the CAL on the display disappears the calibration is done.
  • Step 9: Check the auto dim feature by putting a bright light in front of the mirror sensor (back-side of mirror). The mirror should be bright and clear. Now cover the sensor with you finger and it should darken considerably. This works backwards of my wife's Grand Prix OEM mirror. It has a rear-facing sensor that darkens as it sees light intensity going up and lightens when there is no light.
  • Step 10: Grab a cold beverage of your choice and see what other project needs to be done.