Gentex/ Donnelly Auto Dimming Rear View Mirror Important info

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citadel

citadel

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if you installed a Gentex/ Magna-Donnelly auto dimming rear view mirror and are having issues there is a solution available.

Issue:
The self-dimming mirrors are prone to failure, esp. the oval ones. Seems to be a function of age and heat exposure. What happens is the seal breaks down and the electrically sensitive fluid inside leaks out. If it gets on the interior and allowed to sit, it will stain or corrode what it touches. There are some reports that it contains mercury and is quite toxic if inhaled. Yours might not have leaked all the way out yet, which is why some of it dims and part doesn't. But it will eventually all leak out.

here is a description from another forum on the issue:

So I had my car parked facing the sun for a few hours yesterday, and came back to find the rear view mirror with what appears to be a bubble of liquid inside it behind the glass. Everything in the mirror is blurry, and there is a lighter colored bubble in the top center behind the glass.

Anyway... there is a 3rd party company that is now covering these issues for Magna-Donnelly... Sybesma's Electronic's..

here is their note to me when I contacted them:

Thank you for contacting us. The cost for a mirror exchange is $75.00 plus shipping/handling to the United States. If you reside outside of the USA, please contact us for pricing. You will be required to return the defective mirror and a pre-paid label will be provided for you to do so.
Please note that we do not support mirrors with the home link option.
The attached form will need to be completed and pictures of the following will need to be included for us to determine what mirror it is that you are in need of.
-Front and rear views of the mirror
-The plug (number of pins and wire colors are helpful)
-The mounting bracket located on the windshield
You may send payment via email when your order is submitted otherwise, we will contact you when you mirror is ready to ship for that information.
Do not open the black casing surrounding the mirror as this will cause damage and the unit will no longer be valuable as an exchange and you will be charged the full purchase price of $200.00.
Thank you,
Sybesma’s Electronics
616-392-6911



Here is a pic of my failed mirror:

Also the replacements dont use liquid anymore.. some type of solid polymer is now used...
Picture 192.webp
Picture 184.webp
 
Hmm, I built a machine that fills & checks mirrors at Gentex last Summer, so they still use liquid. I was an engineer at Donnelly long ago, still building machines for them too. My brother used to work at Sybesmas when they were a small electronics shop a mile from my house, they're into mirrors now? I'll have to see if they need any machines built. Maybe I can find out what they're doing with these mirrors. It seems unlikely they can simply stick a new mirror cell in there without some special equipment. They'd have to get the mirrors from Magna Donnelly or Gentex, you need a whole lot of expensive machinery and carefully guarded technology to make them.
 
I've been wanting a mirror with outside temp and compass in it for years. Any suggestions on brand/price/source?

DougM
 
I have a Magna 19697 that came in my 80. It all works fine except the temperature, which is wildly inaccurate. Does anyone know how the get a replacement sensor? Sybesma is out of this business (not even called that anymore), and Magna won't answer a phone anywhere in North America. I'm about to just remove and junk it, but it sure would be nice if the temp worked. I didn't see anything that would give me a clue how to source my own from Mouser or whoever, but I'm open to that, if anyone know how to determine the specs.
 
COS80 said:
I have a Magna 19697 that came in my 80. It all works fine except the temperature, which is wildly inaccurate. Does anyone know how the get a replacement sensor? Sybesma is out of this business (not even called that anymore), and Magna won't answer a phone anywhere in North America. I'm about to just remove and junk it, but it sure would be nice if the temp worked. I didn't see anything that would give me a clue how to source my own from Mouser or whoever, but I'm open to that, if anyone know how to determine the specs.
Click to expand...
Is there an external sensor?
 
COS80 said:
Presently, no. I haven't paid attention though.
Click to expand...
That would rule out ambient heat from the engine compartment versus gauge inaccuracy. If that condition still shows inaccurate readings, then maybe post a picture of the sensor itself. It's likely either a thermistor or a thermocouple, I would guess.
 
COS80 said:
Sensor, presently below RH headlight.

View attachment 3633466
Click to expand...
Ok, spit balling here. I'm fairly sure that's going to be a thermistor (resistor who's resistance changes with temperature). If you have a decent multi meter, unplug the connection at the mirror and check resistance across the sensor leads. Then unplug the sensor and measure the resistance across the sensor itself. There will be some amount of nominal resistance across the length of cable, but if your two measured values are way off then you have a connection or cable issue. Also, the thermistor is in the tip of that sensor, so you want that out in the air versus up against the belly pan or whatever that is. Ideally out front in the bumper or somewhere with the least possible engine etc heat exposure. If that all checks out then move on to verifying the thermistor itself and replacing if needed.
 
Eyedaho said:
Ok, spit balling here. I'm fairly sure that's going to be a thermistor (resistor who's resistance changes with temperature). If you have a decent multi meter, unplug the connection at the mirror and check resistance across the sensor leads. Then unplug the sensor and measure the resistance across the sensor itself. There will be some amount of nominal resistance across the length of cable, but if your two measured values are way off then you have a connection or cable issue. Also, the thermistor is in the tip of that sensor, so you want that out in the air versus up against the belly pan or whatever that is. Ideally out front in the bumper or somewhere with the least possible engine etc heat exposure. If that all checks out then move on to verifying the thermistor itself and replacing if needed.
Click to expand...
Could be a thermistor or a thermocouple, but checking resistance is a good idea. This position is the third trial - the two previous were as you described. The tip is not actually contacting anything, but it is close.
 
A thermocouple will have two dissimilar wires, and all of the connection pins will also need to be those two dissimilar metals all the way to the mirror. So it might be easy to tell by looking at the wires/pins. That said, if it is a thermocouple and the wiring was altered without using TC wire/connectors then it will throw off the reading since it will basically create more TCs in series.
 
Resistance test was inconclusive. I did move it to a new spot - as far into the bumper as the wire would permit. I'm not going to spend any more time on the cable - if I have to pull the cable out, the whole thing is coming out. If the new location doesn't help, and if Magna doesn't respond to my last request by this weekend's trail ride, I'm just going back to a stock mirror. It interferes with the sun visors, anyway.
 
I was looking at the Gentex stuff to upgrade my RVM. Glad I know now about their shortcomings.
 
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