Installing an Auto-Dimming Mirror with optional Compass, Temperature, and Homelink

Created: April 11, 2005

Last updated: April 11, 2005

Author/source: Greg Zapf

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Tools Needed:

Parts Needed:

Total Time: 2-3 hours, adhesive curing not included

A word on sourcing the Mirror kit.

You have several options, in order of greatest expense:


This is not the "authoritative" way to do this... it is the way I did it, and it worked. If you do this and the windshield shatters, your car explodes or tears a hole in the space-time continuum, etc... I accept no responsibility.

This document does not substitute the documentation that comes with your mirror or your mirror mounting kit. I strongly recommend reading and understanding whatever instructions you receive with those items and using this as an application guide for the DeLorean. Also, I highly recommend reading this whole document before you begin.

Step 1: Mirror Mount

Install the Mirror mounting base. For my particular mirror, it appeared that the optimal place for the "button" to mount was about 2" below the black rectangular spot normally used in the DeLorean. Metal buttons are known to crack DeLorean windshields if glued directly to the glass, so a plastic button is recommended. If you MUST use a metal button get the glue insulator pad from a DeLorean vendor or other source that knows what this is. An optimal button would be one that matches the vehicle the kit was intended for (i.e. Mazda 3) As the instructions vary greatly with the different type of adhesive used, I will not post the details here.

Step 2: Temperature Sensor Mounting

If you don't have a Temperature read-out on your mirror, congratulations: almost half of the fun is over, proceed to step 3. :-)

The sensor is usually mounted in the front grill of the vehicle, and the other end should connect to the harness. This means finding a suitable point at which to route the cable through the firewall. I chose the grommet used by the trunk release cable. (Figure 2) First, working from the luggage compartment, pop out the grommet for easier access. Then, lace through approximately half of the temperature sensor cable. My kit came with a cable cover for the front part, so I simple slid through almost all of the exposed cable. Replace the grommet.

Remove your trunk carpet. Unscrew and remove the covering over the gas filler tube. (Figure 3) Bend your coathanger tool in the middle about 130 degrees and tape the sensor to one end. (Figure 4) Route the cable under the car, to the left (from driver perspective) of the brake master cylinder. (Figure 5) You can continue the routing by reaching through the wheel well. Having two people is helpful, but not necessary. I also did not need to lift my vehicle; however, my front springs are not yet lowered... your mileage may vary.

Pull the cable across the harness in the front and to the area behind the very left of the bottom grill. Unless your car is lifted, the next part must be done blind / watching from the front. There is a small gap in the plastic behind the grillwork in the upper left. (Figure 6) Your temperature sensor clip can go over the plastic edge, placing the sensor tip just inside the area visible from the grill. (Figure 7) Once accomplished, use the cable ties to secure the sensor cable. (Figure 8)

Step 3: Routing the Interior Harness

If you have a temperature sensor, you'll need to lace the wire above the steering column so that it falls to the floor near the trunk release. This is "bend backwards and stick your head under the dash looking upwards" type of work.

In my '81 DeLorean, the A-Pillar is glued in place. I've read that in later cars it was clipped in place. If you can easily remove your A-Pillar, it will save you a lot of effort. If not, you will need to detach the pins of the mirror harness from the mirror connector. On my connector, there were some very small holes above each hole for the connector pins. By inserting a fine sewing needle into these holes (Figure 9), you can release a spring clip and pull out the individual wires. (Figure 10) It will not be easy, but keep at it and you will succeed. My Mazda harness had 3 wires (plus the two from the temperature sensor which weren't yet connected). Do make note of which wire is inserted in which hole, as you will need to put them back later. :-)

Protect the metal connectors by wrapping them together in electrical tape. If you have a temperature sensor, include those pins as well, and I recommend wrapping together the two cable parts to make a good harness.

An alternative method to route the wire is through the passenger-side A-Pillar. Credit goes to Jim Reeve for finding this. If your headliners are off, you can pull down a length of the wire that powers the dome light, and then attach the mirror harness to that wire and pull it back up.
If you are replacing / recovering your headliners currently, or would like to get a head start, this is a great opportunity to avoid some more work. If your headliners are removed, you can skip the following paragraph

Pull up the weather strip that covers the headliner around the A-Pillar. Prying up about 6 inches worth is all that's necessary. After that, peel down the headliner fabric and foam so that you can see where the headliner board is against the top of the car. With your fingers and / or screwdriver, carefully pull down the headliner board so that you can see the top of the A-Pillar covering where it is glued against the top of the car. (Figure 11)

Using your screwdriver, carefully separate the A-Pillar covering from the top of the car. Now insert your straightened coat hanger and feed it all the way down the A-Pillar until you can see it when looking beneath the dash. (Figure 12) You'll want a few inches beneath the dash so that you can attach the harness. (Figure 13) During this step, the straighter the coat hanger, the better, so do spend time up front unbending any little kinks you can. Also, when moving in and out of the vehicle at this point, exert caution not to poke yourself with the length of hanger extending from the top of the A-Pillar.

In the footwell area, tape the harness securely to the hanger, doing your best to smooth out any bumps. (Figure 14) Lay out the rest of the harness so that it will feed upward without catching on pedals, etc...

Pull slowly. If the hanger seems stuck at any point, check the harness in the footwell to be sure it's feeding okay. If so, you may push the hanger back down a little and try pulling upward again. Once you've pulled enough of the harness out through the top (Figure 15), untape it from the hanger.

Pull up enough harness to reach across to the middle of the windshield, plus additional length to route down from the headliner to the mounting point, and over to the side of the mirror where the connector attaches to the mirror. (i.e. more than it looks like you need by almost a foot)

Now, lace the harness back between the top of the car and the headliner board (Figure 16) so that it appears near the windshield. Pull it all the way across to the center of the windshield, tucking the exposed harness between the roof and headliner until you just have the harness sticking out over the mirror mount.

Step 4: Testing and Attaching

Unwrap the metal connectors on the end of the harness, and re-attach them to the connector block. (Figure 17)

Back in the footwell, you should have the other end of the power harness, consisting of +12V constant, +12V accessory, and a ground. My kit had a ring on ground, and male tabs on the power lines, and included two snap on T-Connectors. If you look at the harness that runs up the steering wheel, you will see a couple of relevant wires: Brown and Red striped is constant +12V. White and Green striped is +12V Accessory. Although my pictures show slightly different connections, I was using wires that attached to the same things further down. (Figure 18) I found that the bracket holding the trunk release in place was grounded, so I secured ground to the bottom nut there. (Figure 19) Using that ground, I recommend testing the lines before you tap into them, in order to be sure of what you're getting. Once everything is attached, cable tie everything securely.

If your mirror mounting adhesive is done curing, you may attach the mirror, otherwise just hold it up. Plug in the connector. With the ignition key off, you should see no change. After turning the ignition key to accessory, any read-outs should light up. Further, if you shine a light at the mirror surface and cover the photoresistor in the back (toward the front of the car), you should witness the dimming magic. (Figure 20)

If your kit came with a wire cover, it's kind of awkward for the DeLorean, but it can be used. At this point, tidy up... re-attach the gas-filler tube cover. Put your carpet back. Pull the headliner back up to the edge where it was glued and optionally rubber cement it in place, or just secure it with the weather strip. You may want to use the screwdriver to push the headliner fabric up under the weather strip. (Figure 21)

Final Thoughts

Congratulations! With this one modification, you can add several features to your DeLorean that it never had before:

Another thought that --of course-- occurred to me after installation is that you can use this opportunity to route additional wiring for other accessories: I've had it installed for a few weeks now, and I can only come up with the following complaints:

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