B4 side mirror confusion

ETKA shows three part numbers for the starboard mirror; two of them say "convex" and one says "aspherical":

357 857 522 A,
357 857 522 B,
357 857 522 C.

1. What's the difference between them? None of them show up in the catalogs of US distributors, but I can get all three from European eBay sellers, mostly used.

2. My wiring diagrams show that the heating elements are powered by the defogger switch, but research shows forum posts that claim the neutral position on the mirror adjustment switch is what turns them on, the ease of which is responsible for a high failure rate. Which is it?

Following for information... I'd be interested to know the Euro sources where you've found heated mirror glass, I've come up empty...



Sent from my XT1097 using Tapatalk

defogger switch turns on both rear glass defrost, and mirrors

it wasn't until the Mk4 that the neutral position of the mirror switch did that. B4 doesn't have a neutral position, IIRC, it's just L or R.

Some models did wire the mirrors to switched power (always on) before Mk4, but I'm pretty sure B4 is switched. You can test it with a meter on the pins if you like.

357857522C is unheated.

357857522B is heated.

I had read that B3 (same mirrors as B4) were always on heated but I have no idea now where I read that. It would make sense though as there are no other switches to control them. Same with the heated washer nozzles in the cold climate package.

Steve

ETKA says all three are heated. Local dealer says 522B is correct.

vanbcguy said:

Following for information... I'd be interested to know the Euro sources where you've found heated mirror glass, I've come up empty...

Click to expand...

Here's one:
http://www.ebay.com/itm/Side-Mirror...ash=item4d4ec63944:g:~kIAAOSwXeJYLFyb&vxp=mtr

I sent them a message asking if there's any words on it (I damn well know that objects are smaller in a convex mirror; I don't need a reminder getting in the way), and if they'll combine shipping with a flat port-side one. Will update with how that turns out.

Latvia is one of the smallest countries in Europe, but for some reason has a lot of eBay sellers that sell used and new car parts. I've never had issues. It's not Nigeria...

moroza said:

ETKA says all three are heated. Local dealer says 522B is correct.


Here's one:
http://www.ebay.com/itm/Side-Mirror...ash=item4d4ec63944:g:~kIAAOSwXeJYLFyb&vxp=mtr

I sent them a message asking if there's any words on it (I damn well know that objects are smaller in a convex mirror; I don't need a reminder getting in the way), and if they'll combine shipping with a flat port-side one. Will update with how that turns out.

Latvia is one of the smallest countries in Europe, but for some reason has a lot of eBay sellers that sell used and new car parts. I've never had issues. It's not Nigeria...

Click to expand...

BTW, there's no difference in the glass for heated / unheated, the heating element is behind the plastic that the mirror glass is stuck to. It looks like the auction you listed is providing you with the mirror glass and the plastic base that it's stuck to.

Rock Auto sells mirror glass for B3/B4 cars, not very expensive either, but you're not going to like the passenger mirror, it has the dreaded writing on it like factory glass. Just look under the body category in the online catalog.

If your plastic mounting pieces are ok you could get by with just the glass part and you wouldn't need to get them out of Latvia either.

Steve

A few days ago I installed the one in that eBay link. No words on it, seems good quality, shipped from Delaware (?)