Turn Signal Failure (Inop)

[_Nick]

Long story short, I got pulled over, put on my right turn signal, then put on my hazards, put the blinker stick thing in the "neutral" position, turned off the car and removed the key from the ignition, then turned off the hazards. After the car was off for about 5 minutes with the daytimes on, out of no where my turn signals wouldn't work. No left, no right. Hazards worked fine. I checked the fuse and it was fine. I checked every fuse actually and none of them were popped.

I don't know what could have caused it. The bulbs I have in there are new, I put them in probably a month ago. They are also the correct bulbs. I'm 99% certian it has nothing to do with the fuse or the bulbs. After doing a little surfing on the web I found that it could possibly be the 'relay' thats contained in a plastic black box on the firewall behind the fuse box. I'm guessing its the 'Turn Signal Relay'? I don't really know what else could be the problem. I've gotten a new engine harness less than 20k mi ago. I have 155k mi on the car now.

Is there any way for me to check the relay to see if its good or not? I don't have a voltmeter. Could the soldered contacts in the relay be re-soldered? If so, I could just do that myself. I suppose its not the biggest problem, but I would rather not be driving around with no blinkers. Can't afford another ticket. lol.

I'm about to go out and look at it and see if there are any visual indications of the relay failing. I doubt I'll have any luck.

[_Nick]

Okay so I was looking at the relays and I noticed there were two that had fuses in them. A blue relay and a green one. I decided to pull the fuse of the blue one and wouldn't you know it, the fuse was blown. So I'll be running to Pep boys tomorrow morning and praying to god that I only need the fuse and not the relay. I didn't check the green one, I'll do that tomorrow.

Now... its sleep time.

[NW_Merc]

If the fuse doesnt fix it, the stalk control can go as the contacts wear and results in you having to replace it. This could cause the problems you're experiencing too.

[_Nick]

Well, it turns out that the relay with the blown fuse was actually the relay for the electric fans on the radiator. The relay I was actually looking for was the big black one on the right side of the fuse box. I took the plastic housing off and looked at the circuit board and soldered contacts. They seem okay with a little corrosion here and there, but nothing telling me that I should replace it. The contact for fuse 6 which is the turn signal fuse looked fine, but I'm going to remove the old, possibly worn solder and replace it with new solder. Hopefully that will fix the problem, but I highly doubt it.


If the fuse doesnt fix it, the stalk control can go as the contacts wear and results in you having to replace it. This could cause the problems you're experiencing too.

I assuming the 'stalk control' is the switch witch allows you to select the blinkers/wipers? If thats the case then I might as well take apart the steering column and check that out too. Thanks for your advice!

I wish I could find a wiring diagram or some kind of schematics somewhere.

[_Nick]

Did a little more research and I decided to go ahead and buy the new relay. This is it here:
http://www.joetlc.com/wiper-relay-mercedes-benz-c220-c280-e320-e300d-p-6604.html

It seems like some resistors on the relay board are damaged and worn out. I tried crimping the connector a little for the 6th fuse but it didn't make a difference. I honestly don't think that the stalk control is the problem and I realized that taking apart the column is more trouble that its worth right now. Hopefully the new relay will fix my problem.

It kind of make sense because I've been having some problems with my speedo as it likes to work when it wants too, and this relay is also in control of the cluster. Maybe this will fix both of my problems. Hopefully, I'm usually not that lucky though. LOL

[SD202]

Im having the same problem. Im almost certain mine is the stalk control. As all fuses and relays have been replaced and ONLY my right turn signal is out hazards and left turn signal still work. all fuses are good as well as the dual filament bulbs. its frustrating and puzzling because i had an issue with my brake lights not working in a similar mannner the lights were out but all fuses / relays / switches were good. had my wiring harness checked out and they told me its all good as well ( at the dealer) going to be getting the turn signal "stalk" replaced next.

[strictlyspeakin]

the speedo might be sticking to the 0 (rest) pin. Take the cover off and clean it up.

I did have a stalk fail on me so it is possible it went bad.

[_Nick]

Im having the same problem. Im almost certain mine is the stalk control. As all fuses and relays have been replaced and ONLY my right turn signal is out hazards and left turn signal still work. all fuses are good as well as the dual filament bulbs. its frustrating and puzzling because i had an issue with my brake lights not working in a similar mannner the lights were out but all fuses / relays / switches were good. had my wiring harness checked out and they told me its all good as well ( at the dealer) going to be getting the turn signal "stalk" replaced next.

Yep thats my next step. Haven't really messed with it since I got the new relay. Which... did nothing. But I suppose it couldn't hurt to replace anyway.


the speedo might be sticking to the 0 (rest) pin. Take the cover off and clean it up.

I did have a stalk fail on me so it is possible it went bad.

The speedo IS sticking. A nice bang on the dashboard usually gets it working again, but I hate treating my Benz like a Chevy. LOL. I'm going to give it a looksy once I get the new stalk. Thats probably the root of my problems.

Thanks guys.

[anf6789]

does your rear defroster work? its on the same relay as the turn signals. the light will not stay lit on the button. Most likely it is this "multifunction relay" mine went slowly and then completely died and turn signals would not work. should fix the problem.