Auto-dimming rearview mirror failure

[2004_blue_zhp]

Hi all,

My rearview mirror just failed. It's an auto-dimming unit on my 2004 ZHP coupe. I have the car alarm and auto-sensing wipers in my car. In a perfect world, I'd love to just buy the replacement for it. But when I look around online, I see only the manual dimming options with the clown nose (for around $200).

I've tried talking to the folks at radar mirror (the repair service in texas), but they won't repair E46 mirrors (something about how it's the circuit boards going bad, not just the glass, so any repair would break again as soon as it was installed).

Anyone have experience sorting this out? It's not the end of the world for me to go to a manual mirror, but would love to know if there are better options.

[az3579]

Radar mirror not repairing E46 mirrors is news to me, considering mine was repaired by them several years ago. It's still good to this day...

Also, nobody should be paying anywhere close to $200 for a manual mirror. Check eBay; you should be able to pick up a good used autodim one for less than $100.

Sent from my Pixel 7 using Tapatalk

[2004_blue_zhp]

That's so weird! I sent mine to them, only to get a call from the owner saying how the boards frying in them is what causes them to go bad, and that when they swap the glass, they re-break instantly when plugged back in. That's super frustrating.

[cakM3]

You can swap in E90 auto dim mirrors if the one on your BMW is bad. I currently have an E90 hidden compass/homelink recessed clown nose auto dim mirror in my ZHP.

Regarding your auto dim issue it's an issue with the manufacturer of your auto dim mirror. Apparently there's an issue with the circuit card inside the auto dim mirror that is causing the auto dim mirrors to fail. The issue you're having. My recommendation is to source another auto dim rear view mirror and swap it in. As long as you don't have the BMW Assist auto dim rear view mirror the replacement mirror will be plug and play.

If you have the BMW Assist auto-dim rear view mirror then you will have to pull out pins 4,5,6, & 7 so that you don't fry the electronics in the new mirror.

Here is a link to an auto dim rear view mirror I know works in E46

https://www.ebay.com/itm/32457959545...Bk9SR8Cl55eoYg

[///Mark_D]

I've got about a dozen autodim rearview mirrors that I've pulled from salvage cars if you are interested. Typically most E46's are equipped to swap mirrors between E90 3 series and E83 X3, and E53 X5.

The autodim mirrors with integrated compass, homelink, and low profile clown nose are the most sought after variety, and are relatively common. I've swapped one in both my 2004 325i sedan and 2002 325i wagon.

The only potential hangup is if your car originally came with BMW Assist and has an SOS mirror. Those cars are wired differently than non-SOS cars, and would damage a non-SOS mirror if plugged in. To resolve the issue, you just need to disconnect pins 4, 5, 6, and 7 from your car's mirror harness, and then all non-SOS mirrors will be plug and play.

Convertibles are also another outlier, as they have the electronics for the remote key FOB lock/unlock functions integrated into them. There is a separate module in the C pillar to handle these functions on sedans, wagons, and coupes.

More info here as well:
https://www.e46fanatics.com/threads/...#post-19028661

[John in VA]

I was surprised to find my 09/2005-built ZHP coupe has a manual/non-auto-dimming mirror. I obtained an auto-dim mirror with compass/Homelink/bigger clown nose (like on the left in Mark's photo) & all functions worked great when I installed it into the 02/2002 325xi, but no luck in the ZHP. Haven't investigated what wiring I'll need to add or move to get it to work. I figured with that late a build date it would be compatible. Maybe there's a harness tucked up there somewhere!

[cakM3]

I was surprised to find my 09/2005-built ZHP coupe has a manual/non-auto-dimming mirror. I obtained an auto-dim mirror with compass/Homelink/bigger clown nose (like on the left in Mark's photo) & all functions worked great when I installed it into the 02/2002 325xi, but no luck in the ZHP. Haven't investigated what wiring I'll need to add or move to get it to work. I figured with that late a build date it would be compatible. Maybe there's a harness tucked up there somewhere!

John, take a look at this thread from e46Fanatics. It should help you to get the autodim rear view mirror to work in your car.

https://www.e46fanatics.com/threads/...irror.1097788/

[John in VA]

John, take a look at this threat from e46Fanatics. It should help you to get the autodim rear view mirror to work in your car.
https://www.e46fanatics.com/threads/...irror.1097788/

Thanks, Charlie. I have that link bookmarked to study next time the car is home with me.

[2004_blue_zhp]

Update:

After reading the above, I did two things. First, I asked RadarMirror to replace my mirror glass with non-dimming stuff (for a lower price) and send it back to me. Second, I bought a used auto-dimming mirror on eBay for about $75 (it was an e46 unit that looked 100% identical to the one that broke on me).

Both got here this weekend and I installed the eBay unit. The unit looked perfect when it was installed (no visible damage). When I turned on the car (it was getting dark out), things looked to be auto-dim nicely. However, within about 30 minutes, the mirror proceeded to destroy itself. Bubbles everywhere. Clearly was about to explode. Pulled over to a gas station and managed to get it out before anything went horribly wrong. But a photo below makes it pretty clear something awful was about to happen.

I swapped in the RadarMirror "non-dimming glass" one, and everything is stable for now. Clown nose works. Mirror doesn't dim, but also doesn't threaten to ruin my interior.

So what's going on here? Is there something wrong with the wiring harness in my car that's causing mirrors to grenade themselves? Is it possible the one I bought on eBay had some fried board in it that was just waiting to nuke its glass as soon as it was plugged in (to any car, not just mine)? Who would bother fixing up a unit to just that amount of brokenness only to sell it?

I'm fine to live with what I have now. But if I ever found a good deal on an autodimming mirror, should I be afraid that my car is just going to nuke an otherwise good part right after installation?

[John in VA]

If your car has SOS & you didn't pull the wire(s) for that before plugging in a non-SOS mirror the result will be a damaged mirror, from what I've read.