I've been searching the archives, have fund useful info for replacing rear hatch struts, and I intend to post pictures of my project, as well as a few other things.

What I'm more uncertain of are these issues:

1. The sunroof is shut, and the switch doesn't open it.
2. Of all the speakers, only the one in the rear passenger's side seat works
3. Windshield washer doesn't spray.
4. The seat adjustment control doesn't raise or lower the headrests.

My thought is that these are all unrelated, and common problems. I should treat them individually -- first, check to clear the sprayer nozzles, then look at the lines, and finally look at the water pump or grommet.

And the radio unit probably has its own unique problems.

And if the sunroof is similar to my old 123 coupe, the cable is probably gummed up in the housing, and the felt pads are poorly lubricated. Etc.

But I wondered if anyone had insights about some common cause.

I think the main engine wiring harness has been replaced.

Is there another electrical gremlin that could knock out several things at once?

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1995 E320 (2009 - current)
1985 300TD Turbo black (2007-current)
1983 300TD Turbo red (2008-2009)
1972 280SE (2004-2007)
1977 300CD (2003-2004)
1976 240D (1999-2003)

I think you're pretty much on target. The only thing is the headrests: you can remove the seatback and replace or repair the broken plastic gearholder with duct tape. Also, the radio may be OK and it's jsut the speakers that have given up the ghost. Search in the audio forum for how to access them.

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Prost!

We have the original speakers in our 1994 E320 wagon and have the same problem... one or more speakers go out regularly. When one goes out we turn up the volume really loud for a few minutes and amazingly the dead speaker comes back alive. Assuming it's some sort of electrical issue between the stereo and speaker, and not the speaker itself. The common fix is to get a new stereo and speakers and rewire the whole thing. It's not worth trouble shooting and repairing the original equipment, which is not that great to start with.

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Michael

1988 300 SL (5 Speed)
1994 E320 Wagon
1997 C230

A closed, watertight sunroof on a 15 year old car is about as good as it gets.

I agree you are on target. The speakers have paper/cellulose cones and just deteriorate over time. They aren't that great to start with.

Sunroof you are probably spot on, my experience is that if the roof gets used and properly lubricated they are pretty robust, however I think the majority do not get used and the felt dries/lube gets gummy and strains the system causing failure or finicky operation, dealing with this now on a 500SEL.

Washer, spot on, check the orifices and go backward to the pump.

Headrest, may be a bad switch, possibly a short, or the gear may have separated from the rail, remove the seat back with the two screws on the bottom of the seat back and pull the panel straight down. The mechanism will be right in the middle of the seat and easy to inspect.

Good luck!

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1981 300TD
2005 C55
2004 E500
1999 ML430
1992 400E
1998 C43
2001 SL500
1988 300SEL
1986 190E 16V
1991 190E 2.6

A buggy radio volume control is a systematic problem for these models. It's a $100 fix from LaJolla Audio.

Do you hear a motor noise in the backrest when trying to operate the headrests?

Do you hear a motor noise when trying to operate the windshield squirters?

Yeah, with the passenger headrest, I definitely hear a gear turning, but it's teeth aren't biting. On the driver's seat, I don't hear anything.

I didn't hear a motor noise when I tried the washer, but a little fluid weeped out onto the hood. I was driving at the time, and I have yet to really address this issue. All I did was take a casual look: The tank is full of what looks like soapy white water and the hoses look like they're in normal condition. I suppose that if someone was just using water in the tank -- a foreign notion in my climate -- that increases the odds that the nozzles are blocked with lime or minerals or other junk.

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1995 E320 (2009 - current)
1985 300TD Turbo black (2007-current)
1983 300TD Turbo red (2008-2009)
1972 280SE (2004-2007)
1977 300CD (2003-2004)
1976 240D (1999-2003)

What's the fix, a new head unit?

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1995 E320 (2009 - current)
1985 300TD Turbo black (2007-current)
1983 300TD Turbo red (2008-2009)
1972 280SE (2004-2007)
1977 300CD (2003-2004)
1976 240D (1999-2003)

Your radio problem might lie in the amp. The best source for service on these units (head units and amps) is Becker themselves at http://www.beckerautosound.com

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Regards,
Aaron

I understood that they replaced the volume control on the radio. It doesn't use a pot, it uses some fancy electronics. (I think it was a step backwards in technology).