This article will be of interest to anyone replacing the rear view mirror in their General Motors (GM) or other vehicle, whether you are purchasing a replacement mirror from GM SPO, Gentex, Donnelly, or another manufacturer.
Installation information is included for Do-It-Yourselfers (DIY), including wiring harness connector pinout data.
Perhaps the most valuable tip we can give to a vehicle owner planning to purchase a replacement mirror is COMPARE PRICES !
The U.S. government can throw as many billions of dollars at General Motors as they wish, but they’re unlikely to change the fundamental problems at the automaker. Problems that have brought what was once a cornerstone of the American economy to the brink of extinction, dependent on a government bailout for it’s survival.
GM is not competitive for many reasons. They are hobbled by high labor costs. They lag in innovation, particularly in the area of electric and hybrid vehicles. In our opinion, they can’t compete with Japanese auto manufacturers on quality (or perceived quality) or customer loyalty. They’re certainly not competitive on pricing when compared to aftermarket parts suppliers. For most vehicle repairs, we think you’ll spend a lot less, and get a better job done at a private garage, then you would at a GM dealership. This might come as a shock, but in our opinion, Mr. Goodwrench isn’t.
As we’ve stated previously, we believe that their new vehicle warranty isn’t worth the paper its printed on. And GM seems to follow pricing policies usually associated with companies that sell hammers and toilet seats to the Pentagon.
Case in point…
Our GM vehicle was built with an auto-dimming electrochromic rear view mirror. Some rear view mirrors in late-model vehicles are marvels of modern technology, containing On-Star controls, handsfree cellphones, compasses, thermometers, back-up camera displays, garage door openers and other gadgets. But our mirror is just an auto-dimming mirror, with none of these other bells and whistles (see this NY Times article on these “bells & whistles”). On most of the auto dimming mirrors that we’ve seen in GM vehicles, after a few years of service, the magic liquid inside tends to leak out of the mirror. This either renders the dimming feature inoperative, fogs the mirror, or leaves it with an uneven or blotchy reflective surface.
For the past few years, the liquid crystal stuff (or whatever the chemical is) in our mirror has been leaking out, increasingly producing areas on the mirror’s surface that are either always clear or always dark. We finally decided to replace the mirror.
We checked with our friendly GM dealership’s parts department. They quoted us a price of $284.00 for a replacement rear view mirror, excluding the cost of installation.
Almost $300.00 for a rear view mirror ? Sounded awfully expensive to us, so we started to look at aftermarket mirrors. Virtually all American cars use a standard “wedge” type glass mount. The mirror attaches to a glass-mounted “button”, which hopefully stays attached to the windshield when you remove your old mirror from the vehicle.
Our search for a replacement mirror lead us to products manufactured by two predominant manufacturers of automotive mirrors, Donnelly (now called Magna Donnelly?) and Gentex (see company info). It seems that Donnelly sells exclusively to automotive manufacturers (OEMs), and not to the automotive aftermarket. Gentex sells to OEMs (probably the vast majority of their business), but they also sell their products to aftermarket suppliers (in our case, through a distributor named Mito Corporation).
We ended up purchasing a brand new, in the box, Gentex electrochromic rear view mirror that is virtually identical to our vehicle’s original mirror, for under $70.00, including shipping ! That’s less than a quarter of what General Motors wanted for a replacement mirror.
When you consider the fact that GM certainly pays much less for mirrors than the RoutingByRumor Corporation does, that probably equates to a markup of 400%, 500% or more. What word best describes that sort of profit margin ? “Criminal” might be a bit too strong. How about egregious. How about unconscionable. How about stupid ? How many businesses that try to fleece their customers are able to stay in business ? It certainly seems to indicate that GM doesn’t make their money selling cars. They make their money (or at least they did) by selling parts and service; Service that we’ve never been very impressed with in the first place.
The only caveat is that we had to replace the wiring harness connector that powers the mirror, because the Gentex mirror uses a 7-pin connector, while our original equipment Donnelly mirror used a 3-pin connector (our vehicle does not have auto-dimming external mirrors, and the Gentex mirror we installed does not have a temperature or compass display). But replacing the connector was a quick and easy procedure. The hardest part was getting the old mirror off of the windshield. Maybe it helped that we popped our Stevie Nicks album “The Other Side Of The Mirror” into the CD player while we installed our new mirror. To quote Stevie, “This is me talking to you. This is me talking to ya”.
The Gentex mirror we purchased came with very limited hookup information. We found the following pinout data on the Web, and we’re guessing that this information will apply to all Gentex mirrors that use a 7-pin connector.
If you’re trying to figure out what type of connector Gentex (and Donnelly) use on their mirrors, our research indicates that the 7-pin Gentex harness connector (as well as the 3-pin harness connector on our original Donnelly mirror) are “VH” series connectors, from JST Manufacturing. Their U.S. website is at www.jst.com. View JST’s data sheet for the VH series connectors here. These connectors (and the necessary crimp terminals) are available from Digi-Key.
We’re not sure if the wiring color coding is standard on all vehicles, so we would be more concerned with the function associated with each pin on the connector (pin numbers are molded into the connector housing on the wire-side of the connector, but you might need a magnifying glass to read them).
WARNING: Before you begin working on your mirror’s wiring harness, we strongly suggest that you either pull the fuse(s) that protect your accessories (ACC, RAP, ACC1, ACC2, etc., depending on your vehicle), as well as the fuse that protects your backup lamps. In lieu of pulling the accessory fuse(s), remove your key from the ignition and open a door to deactivate the Retained Accessory Power (RAP) circuit, if present and utilized by the mirror. If you really want to play it safe, disconnect your vehicle’s battery, following your vehicle manufacturer’s recommended procedure (for your safety). This will prevent you from blowing a fuse, should you inadvertently short or ground a lead while working on your mirror’s wiring harness.
PIN # …. HARNESS WIRE COLOR …………. FUNCTION
. 1 …………….. WHITE …………………………. +12v (SWITCHED B+)
. 2 ……………. BLACK …………………………. CHASSIS GROUND
. 3 ……………. LIGHT GREEN ………………… FROM BACKUP LIGHT CIRCUIT
. 4 …………….. GRAY …………………………… TO AUTO DIM OUTSIDE MIRROR
. 5 …………….. PINK …………………………….. TO AUTO DIM OUTSIDE MIRROR
. 6 …………….. DARK GREEN/WHITE ……… TEMPERATURE PROBE
. 7 …………….. BLACK/WHITE ……………….. TEMPERATURE PROBE
At a minimum, you must connect pins 1 & 2 (+12V & ground) for your auto dimming Gentex mirror to operate.
Not all Gentex mirrors or all vehicles will utilize all pins, but we believe pins 1 – 5 should be functional on all Gentex mirrors. If your experience differs, please let us know by posting a comment to this article.
Pin 3 is used to clear the mirror when the vehicle is placed in reverse. (DO NOT connect pin 3 to ground, since this will blow a fuse (or possibly damage your mirror) when you put the vehicle into reverse gear.)
Pins 4 & 5 are used to control outside mirrors on vehicles equipped with auto-dimming outside mirrors.
Pins 6 & 7 are used on mirrors that incorporate a temperature display. If a temperature probe is connected, either lead from the temperature probe can be connected to either pin.
Of course, your best source of information is your vehicle manufacturer, or the manufacturer of your new mirror. The above information is believed to be correct, but we take no responsibility for its accuracy.
A Volt-Ohm meter is an indispensable tool for any installer, and we recommend that you use one whenever working on your vehicle’s electrical system.
In our opinion, the auto-dimming feature of the Gentex mirror performs as well as, or better than, our original equipment Donnelly rear view mirror, even taking into account how it operated when our vehicle was brand new. We saved more than $200.00 by not buying the mirror from GM, and probably much more than that, if the dealership would have installed the new mirror for us. The Gentex mirror we purchased appears to be manufactured in the U.S.A. (see this article about their Zeeland, Michigan plant & headquarters buildings), and came with a three-year warranty. We said the Gentex mirror “appears” to be made in the USA, because the only indication we were able to find was the letters “U.S.A.” on the carton label in 2-point type. Not “Made In U.S.A.” or “Assembled In U.S.A.”. Just “U.S.A.”. We’re left to guess that Gentex may be embarrased to admit where the mirror is manufactured. If their products are indeed made in the USA, why don’t they state that fact prominently on the carton, with “MADE IN U.S.A.” clearly visible, like they are proud of it !
We always welcome the opportunity to buy products made in America. We think that buying American made goods, and supporting American workers, is the best way to repair the failing U.S. economy. The U.S. Government’s economic stimulus plans certainly won’t do that.
Let’s hope that if we should ever have to file a warranty claim with Gentex or Mito (their aftermarket distributor), that they honor their warranty better than General Motors has, on the numerous occasions that we’ve had problems with GM products.
As an aside, here’s an article we stumbled upon about another Gentex product, designed to solve one of nighttime driving’s most annoying and dangerous problems.
So the question we are left to ponder is this… Why does General Motors think it can gouge consumers for replacement parts ? If you said “because they’re General Motors”, think again. In our case, they couldn’t. And when you consider the fact that they are teetering on the verge of bankruptcy, begging for federal bailout money, it’s clear to us that their policies, including their pricing policies, are a failure. All of the GM dealerships that have gone belly-up, and those who continue to struggle to survive, in an American new car market that has all but evaporated, are testament to their failed business model. And of course, the decrepit U.S. economy doesn’t help either.
Ya know, our mention of Stevie Nicks’ album “The Other Side Of The Mirror” is quite appropos, because when our GM dealer gave us their price for a new mirror, we suddenly recalled the advice that Alice received from the Mad Hatter… “Better run for your life”.
- Routing By Rumor