The turn signals in my '85 300TDT just stopped working. My past experience with signals in prior (non-MB) cars was that the signal light would come on but just not blink. This was always a faulty relay.

But in this case, the turn lights don't come on at all. Is there a way to diagnose the relay? They're kind of pricey so I'd rather not replace a good one.

I checked the fuse box and all were intact. Or is there another fuse?

Also, I use a digital version of the shop manuals but couldn't find the pages for the turn signals....anyone know what category they are under?

Thanks -Harv

the hazard switch could be the cause, i have seen many that were not quite alll the way off, if they are like that the turn signals will not work, try cycling the hazards a few times and see if that helps

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1967 250 S
1967 280SE
1968 250S
1971 280 SE
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1979 300SD
1983 300 SD
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current:
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I used to have to hit the hazard switch with a little wrench to get it to work. Worked ok till the face of the switch exploded

__________________
1981 300SD 512k OM603

I'll try the Hazard Switch in the AM. I just happen to have a replacement switch for that.

What's the connection between the hazard switch and the turn signals?

Thanks

I had the same problem with my SD. The fuses all appeared fine, BUT the contact points on the turn signal fuse had corroded to the point where although the fuse was still intact, the tips weren't quite in contact with the metal in the fuse box. Try replacing or offsetting that fuse from the center hole and see if that fixes the problem.

__________________
'79 300SD
'82 Chevy Chevette diesel

If the hazard switch is disassembled = 100% this is your issue.

Turn signal circuits are rerouted through the hazard switch = Left/Right join to flash together.





Have a great day.

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didn't really get the "....disassembled = 100% this is your issue" comment but I did remove the old switch and replaced it with the new one this AM, sure enough it fixed the problem.

Thanks for the help -harv

This "problem" will happen again! When it does, simply turn the hazard flashers on/off a few times and it will usually "fix" the problem. Mine has a little sweet spot and I can just rock/wiggle the switch and the signals will come back on line.

__________________
Mark
1983 300TD Wagon
Even a broken watch is right twice a day

I don't know the actual connection, but I learned when member of this forum advised me to take my hazard light switch out and clean it. I did that, and discovered that one of the little plastic doo-dads inside was broken, so the rocker switch inside would not depress fully to activate the hazards. However, during my many tries at disassembling and assembling it back, I discovered that if assembled incorrectly, the turn signals would go on the blink (not work, that is). Try taking it out (its easy enough with a thin flatblade screwdriver) and disassemble it, clean it and put it back together again. Worked for me

PS: This is the first ever piece of advice I've ever given on this forum, so maybe wait till someone else chimes in to agree or disagree with me

__________________
1987 300TD
1984 300D
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BC Canada

That was my error, reading too fast and confused your issue with "turbobenz" post.


Cleaning the Hazard Switch
by whunter
8/28/04
http://www.peachparts.com/Wikka/HazardSwitch

My turn signals stopped working because of the hazard switch. Once that was replaced, everything worked fine. It sounds like this is a common problem.

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1998 Lincoln Continental - Sold
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i have the same problem.. I assume simply removing the switch will not fix it? I was wondering if you can jumper the wires in the hazard switch connector to get the blinkers to work? If so, does anybody know which wires?

Cleaning the Hazard Switch
by whunter
8/28/04
http://www.peachparts.com/Wikka/HazardSwitch

thanks! cleaned the switch, now everything works