97 S320 electrical problem
 

I finally got around to taking my Benz to a shop in order to fix a "smoking" passenger side power mirror. It works but smokes because there are a couple of wires touching and it blows the fuse. That biodegradable wiring issue?. Not really a big deal except that I cant use my memory seats because of it (controls side mirrors too). I'm thinking a mechanic can use some of that shrink wrap and just fix it. The place I brought it to says it needs a whole new mirrow assembly plus paint and a new wiring harness even though it all works till the smoke starts appearing. Price to fix is about $900 with new side mirror housing repainted to match. The guy is telling me that it may need a new motor as well. I feel like I'm being shafted here. Is this problem really as complicated as the mechanic says it is?. He didn't even look at it and is telling me all this crap. I asked if he could just repair the wiring but he says it would cost more in labor doing that than replacing the whole assembly. What do you guys think?

I would pull it off myself and repair it. Those mirrors come apart very easily and once you have it off just go through it. You could replace some wires and have it repaired, if it is the wire, it could be a bad motor. You could just disconnect the mirror entirely, search for a replacement as used for a better price and when you find one replace it yourself. Would you like me to upload a video showing you how to remove the mirror?
Brian

oh, the outside shell of the mirror comes off, so there is no need to paint, if you currently have a good shell, the old one will fit over the new mechanicals, so keep that in mind while looking for a replacement, color is not too big of a deal.
Brian

If I bend the mirror back I can actually see the wires that are touching due to eroded insulation, that is where the smoke comes from. I would love it if you could upload a video showing how to remove the mirror or just tell me. Thanks for the help. :)

Exact same thing happened to my passenger mirror. My mechanic took it appart, fixed a few cables and the mirror was back as new again.

The dealer, of course, wanted to replace the whole mirror and also implied that the motor might be gone. Not true! The motor was perfect, the mirror smoked because the cables made contact.

Labor here is not too expensive and it took my tech guy about 25 minutes to fix, for which he charged me about US$30.00. He says the problem is not the biodegradable wiring but the folding motion of the mirror and the way the cables are laid out on the housing (a design flaw).

He also recommends to leave the cables a little looser than they are originally fitted so the problem will not reoccur. Although, be sure NOT to leave the cables too loose or the mirror will not open all the way as it should. Finally, it is a good idea to lubricate the whole housing hinges with the same grease recommended for the sunroof.

Take the mirror off and individually wrap each wire with electric tape....Presto

I know this will fix it. Know how to take it off without damaging it?. Its hard to find an honest mechanic. I took it to another place as well and they want me to drop it off so they can take it apart and see if the motor is good and blah blah blah. I know the motor is fine..........it works great, its just the wires touching together. I told the second mechanic to just cover the exposed wires and he explained that it may need a whole harness and that the harness extends all the way to the fender and its a lot of work. I just left and I'm going to use .05 cents worth of electrical tape and figure out how to do it myself.

If you don't want to give any power to the mirror, manually tilt the mirror down and towards the car. You'll notice a silver wire clip from the top of the mirror. That holds the mirror in place. Unclip it and fidget with it a little and it should come right off. Worse case scenario, you break the mirror while getting it off, fix the wires and pay $50 for a new one. If you were willing to take it to a mechaninc I think $50 isn't too bad.

Good Luck

If you fold and unfold your mirrors often, the electric tape solution is going to be really a very SHORT term solution.

The motion of the folding motion will loosen the tape very fast and your wires would be exposed again to ambient humidity, hence shorting again.

The best (and cheapest by far) solution is just to clap in new cables and presto.

Mirror sparks and smoke
 

Yesterday morning as my wife cranked up her '98 C280 there were sparks and smoke coming from the drivers side mirror. She hadn't even touched any mirror controls, just started the car....but it's starting to get cooler here and thought just maybe the heater came on. Mirror works fine still and could not duplicate the situation.
Does anyone know at what ambient temperature the mirror heaters are activated and any other equipment it may control? I'll be pulling the glass off and check the wiring when time permits...not overly concerned about it as she is! Hope the wife doesn't read this!!

Tobias MB
190/5.8

I am also curious about the activation temp. I am guessing it is around 50F. I checked the manual and it just says it comes on depending on the temperature but doesn't say what temp. I don't think it controls anything or is controlled by anything, just the temp. I wonder what makes it turn off, or is it on all the time when it is cold? I am sure MB Doc knows!

Mike