W123 Turn Signal stopped working - PeachParts Mercedes-Benz Forum

dave1shere · #1 12-28-2002, 09:34 PM

Hello Everyone,

A couple of days ago my turn signals quit working, then started working again--then quit again and have not been working since. Went to my good old MB CD Manual which only gives me a wiring diagram. I am pretty sure that the flasher is the little black box located between the power brake booster and the hood hinge just in front of the fuse box, but from what I understand from a friend who has another MB, that this relay works the intermittent wipers, hazard flasher and turn signals. The intermittent wiper is working fine but I have no hazard flash or turn signal. Any suggestions would be very welcome at this point.

PS already checked all of the bulbs and they seem to be fine.

Thanks,

Dave

lrg · #2 12-28-2002, 10:46 PM

Check the emergency flasher switch on the center console. If that is between on and off or is broken it will cause your turn signals to act up. If the switch seems ok then unplug it and try the turn signals. The emergency switch is easily broken in that location(you'll note the 124 chasis has the switch moved up to the top of the console.) You may get lucky, if not then move on to the relays and flasher.

Beagle · #3 12-29-2002, 01:23 AM

I agree your problem is very likely your emergency flasher switch. This switch hates "Coke" or any fluid which may have gotten inside to short out the contacts.

The flasher unit is located in the centre console near the shift lever under the ash-tray.

To isolate the problem:

1) Remove the console top cover and unplug the 8-pin plug from the emerg. switch.

2) Take a loop of wire and short out contacts 49 and 30 (next to each other) on the plug. Your indicators should now work normally. If not, then the problem lies either with the flasher unit (expensive) or the ind. switch on the column.

3)The emerg. switch can be stripped right down and then cleaned thoroughly. Spring the plastic casing and the assembly can be slid out. Be most careful to make a sketch and note how to re-assemble the sliding contacts,springs etc or you will be left with a jig-saw puzzle!

#4 12-29-2002, 10:50 AM

The flasher will fail from time to time.. You can get a heavy duty one from a parts house.. I think its a two prong one.. I replace them with heavy duty ones because I pull a trailer with mine often..

However you will also have the same problem if there is a burned out or loose bulb in the turn sig front or rear..

The flasher is the flasher.. It only runs the turn lights and not a lot of other stuff.. If you can get it working you can hear it and feel it work .. Thats the easy way to know if you got the right thing..

Ken

dave1shere · #5 12-29-2002, 06:34 PM

Hello to the 3 individuals that replied to me. Thank you so much. You radvice saved the day, it was my flasher....but not what you think.. I had pulled the center console off about a week ago to reglue a piece of wood that had broken loose where possibly the former owner was trying to pry the console with a screwdriver. In doing so I removed all the switches; therefore on reinstallation, I must not have fastened the flasher plug in good. Special thanks for the tip to jump the flasher plug #49 to #30. That is what lead me to check, and in doing so solved my problem. You may have saved me buying a new flasher.

Thanks Again - Dave

Bear · #6 12-29-2002, 08:51 PM

Dave just a quick tip,pick a spare one up next time your in a breakers.Cars in salvage yards/breakers normally have sound/good flasher relays.
Bear

daftwankie · #7 05-03-2012, 09:26 PM

excellent tip on the emergency lights. worked for me, too.

c123 · #8 06-06-2012, 10:31 AM

Hi all,

I also have problems with my turn signals not working. To isolate the problem I have tried short circuiting plugs 49 & 30 in the emergency light switch and then the turn signals work perfectly. That lead me to suspect the emergency light switch was broken/dirty, so I opened and cleaned it, but no luck. To be sure I ordered a spare emergency light switch, but still no luck.

So, I have working emergency lights and no turn signal with the presumably functional emergency switch installed. With 49 & 30 jumped working turn signals.

What's the next thing to investigate?
Any suggestions welcome.

I have a C123 '84 (with the smaller hazard switch).

thanks
-david

Yumeko-chan · #9 06-06-2012, 12:51 PM

Same thing happened with me; every now and then my turn signals would stop working, and it hasn't been a problem since I replaced my hazard warning switch

c123 · #10 06-06-2012, 01:09 PM

Found it! There was also a blown fuse. Now with the new hazard switch and replaced fuse all is good.

firstdiesel · #11 06-30-2012, 08:56 PM

Okay, when you guys say "not working" are you talking off or no indication? I turn my signal on and it flashes 2-3 times and then stops in the "on" position. Then interior light stays on and the exterior light stays on. If I turn it off and then press the emergency flasher, the flasher stays lit up as well. After a little while of this it all goes back to normal for days at a time and then acts up again. The good thing is that since it is on I can manually use the turn signal if needed.

What is the relay under the ash tray? It seems to be the one making the turn signal "noise/click" because I can barely hear it when the signals do work.

Levin · #12 07-09-2013, 08:06 PM

Hey firstdiesel, did you ever figure out what the problem was. I have the same issue.

firstdiesel · #13 07-30-2013, 08:42 PM

Hi Levin, no I never did find the problem.

I took the flasher relay out from under the ash tray and took it apart. It's really easy, then I cleaned it well with electronic cleaner and cleaned off the contact point. It seemed to work for a while, but it is still hit and miss now.

Someday's it works perfectly and others it will blink 5-7 times and then just stay on. I think the only course for me right now is to just get a new relay, but I have run into transmission problems and that has taken all of my time for now.

When I get a new relay and it fixes it, I'll update the post.

Philip Eglin · #14 09-03-2020, 03:17 AM

Hi Guys

I had the same issue with my 1997 300d. The Flasher stopped working and if you tapped it you might get a flash but eventually nothing. I looked around and could only find reconditioned units , the cheapest being 129 Euro.
I did some research and found that the units start to stick as the get older.

I purchased a bottle of Isopropyl Alcohol for about $8 AUS .I placed the entire Flasher unit in a jar and covered it with the Isopropyl Alcohol. and placed a lid on the Jar ( it evaporates quickly). Let it sit in there for 10 -15 mins and regularly shook to get the fluid right through the parts of the Flasher. The fluid changed colour slightly, but I noticed there was a lot of small particles in the bottom of the jar eventually.
I took it out, shook of excess and then blew it dry. Plugged it in and it has been working ever since.

Worth a try before spending serious money on a 2nd hand unit that may not work !

Skippy · #15 04-18-2021, 09:51 PM

I'm having a similar problem. Turn signals not working. Hazards working sometimes, but not always. Pulled the center console apart and jumpered the 30 and 49 pins on the connector. No joy. Then I noticed the flasher relay wasn't in all the way. I pushed it back in and I got working turns signals and hazards, for about three turns. Now I still have hazards but no turn signals. Hazard switch ($12.50) and flasher relay ($27) are on order. Is there a convenient way to verify whether the turn signal switch itself is good?