Rear View Mirror - Manual vs Auto Dimming?

[StudioWizard]

The mirror in my 2005 2.5i got "floppy". The O ring that wraps around the ball and joint assembly no longer stays attached as one of the ball joint tabs has broken off. I considered super gluing the broken tab to see if I could salvage it, but I think it's going to be too difficult to do, plus it may not really hold. So, I think I'll just replace the mirror.

My current mirror is a manual dimming mirror. I can buy a new OEM part for about $320 with tax/shipping OR I can buy a used OEM in excellent condition WITH Audio Dimming for about $240.

My question is this: Is the Auto Dim mirror good? Can I still manually dim by turning the knob on the bottom or is all dimming accomplished automatically?

Any thoughts and opinions on whether I should stick with a brand new manual dimming IRVM vs a used auto dimming IRVM (which comes with a 90-day warranty, FYI).

Thanks!

 

[BumpyZ4]

The auto dimming mirror is strictly auto dimming there is no manual dimming function. Mine seems to work fine no real issues that I've noticed. Bascially it is one big LCD and they do eventually start to fail and leak the fluid.

 

[StudioWizard]

Does yours have the round knob on the bottom? If so, does it turn and do anything? Has yours failed before and been replaced?

 

[BumpyZ4]

No knob. It only has the "clown nose" which houses the red LED for the alarm system. Yes the original one failed, i replaced it a couple of years ago.

 

[StudioWizard]

OK, good to know.

FYI for anyone interested: many of the sellers on Ebay are advertising manual dimming mirrors as auto dimming... possibly as click bait.

The basic replacement part # for manual dimming is: 51169134400

There are a BUNCH of part #s for the auto dim version all starting with 5116. The rest are:
9134395
4363965
7051897
9125552
7051892

Maybe someone around here knows why that is?

Also, I'm not sure what EC, LED, Radio mean in regards to the mirror designations... I know what LED "means", but not for the mirror. Is there a readout on the mirror or something? And I'm guessing Radio means keyless entry....?

 

[BumpyZ4]

Radio means it is for a roadster as that's where the receiver is for the key FOB. LED is for the alarm (housed in the clown nose). EC stands for "electro-chromatic" i.e. "auto dimming".

 

[StudioWizard]

Ah! Thank you!