WEIRD electrical issue...possibly relays?
Thread Starter
Member
Joined: Nov 2009
Posts: 233
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From: Los Angeles
1993 400E, 1994 E420, 2000 SL500, 2014 C250
WEIRD electrical issue...possibly relays?
Hey there. I'll start off by saying I did search the issue but still need some clarification from some electrical experts.
I was driving my car yesterday and noticed that my power seats and mirrors were not working. After looking around to see what else wasn't working, I discovered the windows and sunroof weren't working either. I figured it was a fuse, but they are all fine.
I then figured out that the seats work fine if the door is open and the push-switch in door jam is open, but when the switch is pushed in (door closed), the seats don't work. Then my mirrors came back and work fine now. I found that when I push the window switches, I hear a clicking noise like normal and traced it to the box on the driver's side, under the rear seat. It clicks every time I push any of the window switches but hear nothing when trying to use the sunroof. I know the switches are getting power.
Does this sound like a relay issue and if so, where is the relay? Is it part of the electrical box/connections under the rear seat, behind the driver? Someone posted that relays are under the hood, under the electrical box, but those were on coupes. I'm at a loss and it's really annoying. Oddly enough this happened the day after it had been raining a lot.
When I searched, I came up with posts that only had the sunroof/window issues but never anything with the mirrors and the weird power seat issue when the door is closed.....
Any help would be greatly appreciated. Thanks
-BJ
I was driving my car yesterday and noticed that my power seats and mirrors were not working. After looking around to see what else wasn't working, I discovered the windows and sunroof weren't working either. I figured it was a fuse, but they are all fine.
I then figured out that the seats work fine if the door is open and the push-switch in door jam is open, but when the switch is pushed in (door closed), the seats don't work. Then my mirrors came back and work fine now. I found that when I push the window switches, I hear a clicking noise like normal and traced it to the box on the driver's side, under the rear seat. It clicks every time I push any of the window switches but hear nothing when trying to use the sunroof. I know the switches are getting power.
Does this sound like a relay issue and if so, where is the relay? Is it part of the electrical box/connections under the rear seat, behind the driver? Someone posted that relays are under the hood, under the electrical box, but those were on coupes. I'm at a loss and it's really annoying. Oddly enough this happened the day after it had been raining a lot.
When I searched, I came up with posts that only had the sunroof/window issues but never anything with the mirrors and the weird power seat issue when the door is closed.....
Any help would be greatly appreciated. Thanks
-BJ
Thread Starter
Member
Joined: Nov 2009
Posts: 233
Likes: 0
From: Los Angeles
1993 400E, 1994 E420, 2000 SL500, 2014 C250
Nevermind...fixed it. It was the fuse. Even though it looked fine, I swapped the #2 fuse (comfort, etc) for the #1 fuse (sunroof) and it worked. Oddly enough, the bad fuse decided to work again because my sunroof is working again (for now). Guess I'm going to buy a bunch of fuses tomorrow and change them all out.
When in doubt, change all your fuses. Cheap and easy preventative maintenance. Hope this helps the others that posted similar issues and never wrote back with the problem solved. If you have the same weird issues I did, check your #2 fuse.
BJ
When in doubt, change all your fuses. Cheap and easy preventative maintenance. Hope this helps the others that posted similar issues and never wrote back with the problem solved. If you have the same weird issues I did, check your #2 fuse.
BJ
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c280
Hate to piggy back on a thread but regarding fuses, would more than one go out at the same time? My sunroof / moonroof, radio and climate control have all stopped at the same time. Is there a relay issue or fuse issue that relates or connects / control all three? I have a 1994 E320 but I imagine W124 model electrical layout would all be identical.
Last edited by saltima; Apr 10, 2012 at 06:10 PM. Reason: to add more details.
MBWorld Fanatic!
Joined: Jun 2006
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1990 300ce 24v I6
I think that could be a fuse, check the box. It has a chart for what fuses control what.
I also think that could be your Convenience relay. Check under the rear-right seat. There should be a relay there (and possibly more fuses).
I also think that could be your Convenience relay. Check under the rear-right seat. There should be a relay there (and possibly more fuses).
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c280
Okay but going back to my original question? Would one fuse control all three or am I looking at three fuses all go out simultaneously? The radio gets power but no volume. The sunroof does not slide back anymore but I get lamp lights. And the A/C works but I can't get the fan or auto climate to turn on. No speeds at all. Three different and unrelated issues all at the same time same day.
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MBWorld Fanatic!
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1990 300ce 24v I6
I had this exact issue and it turned out it was just the regular fuses having micro-fractures.
MBWorld Fanatic!
Joined: Jun 2006
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1990 300ce 24v I6
I usually have difficulty finding the cylinder fuses in regular American Autoparts stores. Its pretty simple to tell the difference. The copper fuses have a gold/copper strip, while the aluminum ones are a dusty white/silver strip.
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Joined: Sep 2008
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From: Dallas, Texas, USA
2004 SLK 230, 1992 300E & 400E
"torpedo" fuses. Go to ebay, "auto parts and accessories" I believe is where they are located, and buy the bulk "containers" of the copper fuses. 8 amp (white), 16 amp (red), 25 amp (blue). They come on their own, individual amperage "blister pacs", probably, like 16 of each on one blister pac (in other words you would buy three pacs). Then change them ALL out, and pitch the pewter (or aluminum or whatever crap the old ones were made from)! Funny thing, aluminum house wiring has been outlawed for 40 years, seems as if that shoulda been a CLUE!
Last edited by larryj; Apr 26, 2012 at 10:21 PM.
