Sudden failure of blinkers, horn, wipers, and rear defrost!
Thread Starter
Newbie
Joined: Mar 2013
Posts: 2
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1999 Mercedes-Benz C280
Sudden failure of blinkers, horn, wipers, and rear defrost!
Hello all, first post here!
My '99 C280 started misbehaving today. My blinkers, wipers, horn, and rear defrost will no longer activate. This happened - likely not unrelated - after I was tinkering with fuses under the hood trying to sort out my other intermittent issue with the central locking and windows going out with no discernible rhyme or reason. The kicker is that my warning flashers still work fine.
So, two questions:
1. I deduce that either: A.) there are two relays, one for individual blinking and one for hazard flashers, B.) there are two separate fuses for hazards and individual blinking, and I messed one up, or C.) the wiper/blinker stalk gave out at a very convenient time but none of this had to do with poking around the fuse box.
2. This is much less important to me, but my windows (usually front driver, sometimes both front), and occasionally sunroof motors decide to stop working. This usually but not always is correlated with either poor remote unlock range or total failure of remote unlock. It happens in all seasons and all humidities, and with no other correlations I can figure out. It seems totally random. Any ideas?
As a side note, I have looked extensively on the blinker/wiper issues and it seems older W202s (per-1998?) had a "multifunction relay" that would cause similar symptoms. Reseating this or resoldering the internal components seemed to be a fix in those years, but my relays look different than what is described. Did something change?
EDIT: I reseated all relays. There is no "N10" relay, I confirmed. This was, in the older W202s, a combination relay that would be the obvious culprit given my symptoms. Instead there are quite a few different relays (see images below).
My '99 C280 started misbehaving today. My blinkers, wipers, horn, and rear defrost will no longer activate. This happened - likely not unrelated - after I was tinkering with fuses under the hood trying to sort out my other intermittent issue with the central locking and windows going out with no discernible rhyme or reason. The kicker is that my warning flashers still work fine.
So, two questions:
1. I deduce that either: A.) there are two relays, one for individual blinking and one for hazard flashers, B.) there are two separate fuses for hazards and individual blinking, and I messed one up, or C.) the wiper/blinker stalk gave out at a very convenient time but none of this had to do with poking around the fuse box.
2. This is much less important to me, but my windows (usually front driver, sometimes both front), and occasionally sunroof motors decide to stop working. This usually but not always is correlated with either poor remote unlock range or total failure of remote unlock. It happens in all seasons and all humidities, and with no other correlations I can figure out. It seems totally random. Any ideas?
As a side note, I have looked extensively on the blinker/wiper issues and it seems older W202s (per-1998?) had a "multifunction relay" that would cause similar symptoms. Reseating this or resoldering the internal components seemed to be a fix in those years, but my relays look different than what is described. Did something change?
EDIT: I reseated all relays. There is no "N10" relay, I confirmed. This was, in the older W202s, a combination relay that would be the obvious culprit given my symptoms. Instead there are quite a few different relays (see images below).
Thread Starter
Newbie
Joined: Mar 2013
Posts: 2
Likes: 0
1999 Mercedes-Benz C280
Alright, I'm just going to keep following up with my tests - I removed the K40 relay unit from the passenger engine bay area, opened the housing and inspected all solder joints. Nothing that I can see indicates any issue with this unit. The fuses in the K40 unit also check out and the actual relay switch itself looks fine when I opened it up. I do not have a multimeter so this is all visual inspection.
I'm just about at my wits end with this, might just take it to the dealer :/
EDIT: Just swapped the K40 switch relay unit (the black, actual relay box) with the one in the trunk. No change, which to me indicates they are both fine.
I'm just about at my wits end with this, might just take it to the dealer :/
EDIT: Just swapped the K40 switch relay unit (the black, actual relay box) with the one in the trunk. No change, which to me indicates they are both fine.
Last edited by dannykansas; Mar 3, 2013 at 05:28 PM.
Junior Member
Joined: Jan 2008
Posts: 17
Likes: 0
Mercedes 300ce
Same problem
I have a 1999 c43 and I have same issues. Driver fron window would stop working then passanger and sometimes roof and rear driver window. Today all dont work on top horn and wiper stopped working and so did the blinkers. Mirrors on dors dont work so no connection to front door modules. Hazards work. Any ideas? I think all connectl at the alarm module? Its been like this for months and battery dies after a month. No matter what battery I install. Also seems to respond with delay when opening or closing using new key and 2 old keys. Car was flooded from the blower fan drain getting clogged. I had communication issues car would not start it got fixed at Stealer but now all these issues are here.
