-   YJ Wrangler Technical Forum (
-   -   Auto dimming rearview mirror with compass and temperature install (

Cobra Jeep 01-06-2013 04:57 PM

Auto dimming rearview mirror with compass and temperature install
Since we all love cool junkyard swaps, here is one I have recently done and really like.
Many late model GM vehicles have auto dimming rear view mirrors with built in compass and temerature displays. What I found neat about these, are they are "self contained" units. Meaning they are not controlled by the vehicle they are installed in. They only need power, ground, and a temperature sensor to work.
Now there are several different models out there. Some older (late 90's) may have auto dim and compass only, others will have compas and temp. Just look at the buttons on the mirror. If one says mirror and the other says comp, then its compass and auto dim only. If it says comp and temp, then it has both. Some of the older (late 90's) will have a small rectangle window for the display, and will only display temp or compass, not both at the same time, while many newer ones will have a larger square display and read both at the same time.
There are also some later model ones with onstar buttons, you dont really want one of those. Some may also have a display for passenger airbag. So might not want one of those. Just look in all the different vehicles in your junkyards and see what has what. Make sure you get the temperature sensor from the grill of the same vehicle you get the mirror from.

I installed a older single display (will only display comp or temp, not both at the same time) in my 79 cherokee. It fit the stock jeep mirror mounting tab. Ran the wires, mounted the temp probe in the grill and its good to go. This specific one I pulled from a 99 chevy suburban.

Now for my YJ I scored a newer one with the larger display that will read both temp and compass at the same time. This specific one I pulled from a 03 saturn vue. I also got the mounting tab off the glass. The windshield in the vue was already cracked from the wreck, so I just used a stiff putty knife to remove the tab from the glass. It knocked out a chunk of glass with it. I used a heat gun once I got home and removed the glass and glue from the tab.
Mirror and temp probe:

Some google searching got the pinout for the wires. Yellow is power, black is ground, and the green/blk and grey wires go to the temp probe. Any other wires can be removed. I only had 1 that I removed.
So now to get the jeep mounting tab off the glass without breaking my windshield. I took a heat gun and worked it over the windshield to heat it up and kept it warm and then heated up the tab and used a thin razer blade and it poped right on off. Cleaned the glass and tab, and glued on the tab for the new mirror.
Now to wire it up. The wires are real small as the mirror draws very little power. I actually used some 18 ga speaker wire and even it was larger than the mirror wires. I ran two down the right side, and the other two down the left side. I ran the wires under the rubber moulding around the glass and down the sides of the dash. You can see the wires on the side, but it doesnt bother me. Hooked up the ground, and the power to a switched 12v source.
Now for the temp probe. Its a funky little thing, made to snap into a 7/16 hole. So I used a peice of thin scrap metal I had and made a bracket for it. I used a 7/16 washer to take up the extra room, as it was ment to snap into a thick peice of plastic.
I ended up deciding to mount it in the drivers fenderwell, I started to mount it in the grill, but it can pick up on heat from the radiator if not moving fast. Also in the fenderwell it mostly shaded from direct sunlight so maybey it will get a better temp reading. I just used one of the fender to grill bolts. Should still have plenty of air flow and the sensor and connector are both waterproof, so no worries about rain.

All hooked up and working. Ignore the "cal" It just needed to be driven in a circle a few times to calibrate the compass. I took the pic before I drove it.

Hope everyone enjoyed the mini writeup. Any questions I will try and answer them.

Unlimitedlou 01-06-2013 05:05 PM

Great write up. I am doing this!

Anticanman 01-06-2013 05:10 PM

Looks nice! I thought about a junkyard rear view mirror until I saw the ones used for backup camera monitors and decided I needed one for a "rock cam".

amc75matador 01-06-2013 06:14 PM


Originally Posted by Cobra Jeep (Post 14742248)
Hope everyone enjoyed the mini writeup. Any questions I will try and answer them.

This post is awesome! thank you

bigbossd1030 01-06-2013 06:33 PM

2 thumbs up here.

Cobra Jeep 01-07-2013 04:56 PM

Had to make a couple stops after work today and didn't get home until after dark. The auto dim works great! Also when I went out to it this morning it was cold, 27* to be exact, and where the temp is displayed would alternate between the temp and ICE. Guess its trying to warm me there might be ice out
Really liking this upgrade. If anyone wants to look them up online, they are made by gentex. If you don't have any luck finding one at your local junkyard they are all over ebay, but can be kinda pricey. Just search gentex mirror and you will find a crapload of them.

roadyrob 01-07-2013 05:48 PM

very cool, me want!

MukYJ 01-07-2013 05:59 PM

Nice, I might pick one of those up next time I'm at the pull-a-part. :thumbsup:

roadyrob 01-07-2013 07:02 PM

found one on fleabay, tested with sensor and wiring instructions, 45.00 shipped. thanks again for the idea.

roadyrob 01-07-2013 07:05 PM

double post.

deathtrap 01-07-2013 10:21 PM

Hay cobra you been lookin over my back fence? I just did this exact thing yesterday. fun project, I got less then $15.00 in mine.

90DesertTanYJ 01-08-2013 08:33 AM

Nice project. I am getting one for the YJ and one for my car too.. Hey Cobra, how about a close up on the temp sensor so I know what to look for. Are they all typically located somewhere in front of the rad behind the grill? I would think the GM ones would look pretty much the same, what did you see when searching the JY? Thanks for the tip on the Vue. I understand S10 Blazers are also good donors.

pasinbuy 01-08-2013 08:47 AM

Nice write up. I do not understand why all vehicles do not have a compass. How many times have we all found out that we are going the wrong way and for the only reason that we do not have a compass in our vehicle?

Happened to me again last week. When you drive in unfamiliar areas a compass is invaluable!

50rck 01-08-2013 09:05 AM

I tried this with a late 90's Buick mirror to my YJ. It didn't work. I did some research into the VIN on that Buick and it needed the computer to work. The Saturn worked for you and makes me want to try it again.

Cobra Jeep 01-08-2013 04:09 PM


Originally Posted by 90DesertTanYJ (Post 14753151)
how about a close up on the temp sensor so I know what to look for. Are they all typically located somewhere in front of the rad behind the grill? I would think the GM ones would look pretty much the same, what did you see when searching the JY?

Actually the temp probe looks different depending on year model I think. The one I installed in my cherokee has a very different looking temp probe from the one I installed in my YJ. Most are just somewhere behind the grille usally tward the center. Make and model will dictate their exact locations and style. So just make sure you get the sensor from whatever you pull the mirror from.
You can see the temp probe setting next to the mirror in the 2nd pic (where its setting on my workbench) Its grey and has a green/blue connector.

Doing some more looking around online, it looks like most of the chevy ones have a higher chance of having the onstar button and the passenger airbag warning on it. While pretty much all saturn vue ones I saw had temp/compass/auto dim only. I searched eabay and they are pretty easy to find on there for not too much if you can not find one local.

Another thing I like about this mirror is that it is wider than the stock YJ mirror, so you get a much wider and better view of whats behind you.

The time now is 07:41 AM.

Powered by vBulletin Version 3.8.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.