Auto-dimming mirror weirdness (1 Viewer)

[bloc]

The other day I noticed a car behind me burning holes in my retinas via the windshield mounted rearview mirror. Odd, as the little green light was lit and I know for a fact the dimming worked when I got the truck a year and a half ago. Then, I notice the side-view mirrors are clearly dimmed as they should be.

Turn off the system with the button on the mirror, the side view mirrors slowly go clear, the center one stays just as it is. Back on, sides dim, center doesn't.

So at this point I assume the sensor in the mirror itself is working, but the dimming function isn't.

Oh, and the mirror lists for $830, I can get one for about $550. Not exactly commonly available used either.

Anyone else had this happen?

I'll be doing more testing with a flashlight over the sensor when it gets dark today but was curious about other people's experience. Search didn't yield anything useful.

Thanks for any info

 

[ceb]

Do you have a hang tag or something on the mirror? There are two sensors on the mirror - one pointing forward that asks "is it dark outside?" and the one pointing back that asks "any headlights back there?"

 

[bloc]

Do you have a hang tag or something on the mirror? There are two sensors on the mirror - one pointing forward that asks "is it dark outside?" and the one pointing back that asks "any headlights back there?"

No hang tags. Found both sensors and assumed those were the functions.

I got some more testing done. In a dark driveway, all mirrors clear. pen light on the rear sensor, side mirrors dim, center doesn’t. Remove light, everything clear. Same if I hit the off button, then on.

These mirrors look impossible to open up and investigate without damage..

 

[ceb]

No hang tags. Found both sensors and assumed those were the functions.

I got some more testing done. In a dark driveway, all mirrors clear. pen light on the rear sensor, side mirrors dim, center doesn’t. Remove light, everything clear. Same if I hit the off button, then on.

These mirrors look impossible to open up and investigate without damage..

Put something over the forward facing sensor and see if the behavior changes (test at night with a flashlight as before.

If there is no change then your mirror is dead and needs to be replaced.

 

[bloc]

Put something over the forward facing sensor and see if the behavior changes (test at night with a flashlight as before.

If there is no change then your mirror is dead and needs to be replaced.

Does the forward sensor control when the side view mirrors can dim as well?

Either way I’ll try it

 

[ceb]

Does the forward sensor control when the side view mirrors can dim as well?

Either way I’ll try it

Yes it does, but I'm not sure if the threshold is the same, but it'll rule out one common issue

 

[bloc]

Well, everything worked fine for over a year then this randomly popped up again. Tried flash lights and tape and covering sensors.. finally just tapping the mirror like I was annoyed with it got it working again.

Figured I’d update for visibility.

 

[TOMSRYD]

That would drive me nuts. What got it to work for a year?

 

[bloc]

That would drive me nuts. What got it to work for a year?

I was messing with it putting tape over the front sensor then shining a light into the rear to simulate night driving during the day, and must have bumped it. It just started working during my diagnosis. Then randomly stopped again after all that time. At the time I assumed brute forcing the light sensor got it working, which is what I tried doing again this time.

I’m assuming I have a slightly loose connection within the LCD dimming portion of the mirror since the rest of the system seems to function as normal (side mirrors) even when the main mirror doesn’t. Thing is I don’t see a way to open it and go digging around trying to investigate.. so hopefully it doesn’t act up often or progress beyond tapping it being the fix.

 

[gaijin]

Well, everything worked fine for over a year then this randomly popped up again. Tried flash lights and tape and covering sensors.. finally just tapping the mirror like I was annoyed with it got it working again.

Figured I’d update for visibility.

Old pros call that "percussive repair" - often used in conjunction with a BFH

HTH

 

[bloc]

Old pros call that "percussive repair" - often used in conjunction with a BFH

HTH

Hah I’ve never heard that.. will definitely be using it in the future though.