Is the dealer wrong?
 

I took my 2000 S500 to the dealer recently about a problem with my right side mirror light. I was told that the turn signal on my right side mirror is not working because of a problem with the whole mirror assembly, not just the turn light/bulb itself, and since this problem is not fixable I have to replace to whole mirror assembly at more than $400, however, the mirror can be moved around perfectly and I've heard this problem can be fixed by simple replacing the light. Is the dealer wrong about this issue?

Mirror Housing-
 

I haven't heard of that before- that's a new one. I will look into that for you... I believe the parts of the mirror housing are all sold seperately. It has a similar set-up as the 2000-2002 W210 bodies.... Should just be an easy fix. :)

I'm aware that in most cases when the turn light is not functioning all it needs is a light replacement, however, the dealer said it wasnt so in this particular case because my problem is not pertaining to the light itself but to a problem with the whole mirror assembly and that to get the light working again I have to replace the whole mirror assembly. I dont understand why you would need to replace the whole mirror assembly when the mirror works perfectly except for that light. Most people tell me that if the mirror can be moved around perfectly there is no need to replace the whole mirror, that I can individually just replace the non-working light.

My best guess is that they replaced the outter shell with the light strip attached and found that that did not work either so they want to replace the whole asembly now which feeds the housing light.

The cover with light separates from the mechanicals of the mirror.

There are electrical contacts between the two parts as well as a wiring harness that's part of the mechanicals.

If contact doesn't happen, one needs new mechanicals.

Attached is scan of the fiche from EPC. Right side of fische shows mirrors with integral turn signals. The light unit is NOT a separate part.

Mechanicals are 220 810 08 76 and list price for this part is $250 and it's $195 here: http://www.trademotion.com/partlocator/index.cfm?siteid=213951

List price for cover/light is $190 and Duval is $148.20 but you have to order 220 810 10 64 with a color-code.

You've been given the correct story and good prices.