You need to replace the emergency flasher switch which also controls
the blinkers. It's the rectangular red thing on the center console.
Just gently pry in out with a dull blade. But be careful not to pull
abruptly. I'd try to clean the pins and reinstall to see I that does
the trick. If not, buy a new one on the net. A Benz dealer with
charge you the list price of $144 for this little gizmo. I bought mine
on the net for half that. Here's the url where I bought mine:
Toblin '79 300D 230K