Sorry if I put this is the wrong place, it seems this forum gets more general help stuff whereas the diesel forum is mostly diesel help.

The blinkers on my 84 300td sometimes don't work...
This is the list of things I've done to troubleshoot the problem.

When the blinkers don't work:
The high beams and wipers still work (stalk isn't totally broken)
Stock clicks back to the middle when I turn the wheel
Fuse is not blown and everything else on that circuit works
The hazards work, the red hazard switch flashes AND the arrows on the dash flash

Then after a while the blinkers will start working again for a few days like nothing ever happened. So it's intermittent, the most fun kind of electrical problem to diagnose

Weird side note, it seems to only happen when I mess with the vacuum lines by the firewall (last time it happened I was working on the vacuum lock system (which I narrowed down to just a bad master vacuum switch )). I'm not sure if this has anything to do with it, if there's some connector right there for the blinkers or if it's a random coincidence.

I am going to assume that when you turn the turn signals on, nothing happens, no lights come on outside and no indicators come on in the dash. In other words, they are completely dead.
If this is the case the first thing to do is turn the hazard switch on and off about 30 times as fast as you can.
What can happen is the contacts in the hazard switch for the turn signals sits closed 99.9% of the time. The contacts tend to oxidize. When the contacts are opened and closed there is a very slight rubbing action. This helps keep them clean and making good connection.
I have seen this fix switch problems many times over the years, so give it a try. It fixed my 500SEL when the turn signals quit sometimes. A free fix is always a good thing. A free fix that doesn't help doesn't cost anything. Nothing ventured, nothing gained.

PaulM

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84 500 SEL (307,xxx miles)

So when I go and test to see if the hazards work, I clean the contacts a bit so then the blinkers work again. I guess that makes sense