E-Z 4 some, hard 4 me!
 

The left-hand turn signal (driver's side)on my '85 380sl started flashing about twice the normal speed. That's easy, I thought, a burnt out bulb. Went around to the front of the car and sure 'nuf the turn signal light was not operating. Took it apart, the bulb tested good with a meter. Swapped it with the passenger side bulb, it worked there, the previously working passenger side bulb didn't work now that it was in the driver's side, same condition, fast flashing left turn indicator, rear left signal lamp flashes fast. Checked for a good ground on the lamp socket, good ground was present. Looked for voltage coming to the lamp when turn signal activated, nothing. Spent more time on the "search" than I shound have and came up with a reference to a poor 4-way flasher switch, played with this, no better. I am now tryng to find where the flasher may be located, as this is the last thing I can think of. Does anyone know where it might be located? Thnx.

I'm not an authority but it sounds like a contact problem. I would clean (scrape) both ground and hot contact points front and rear... also the contact points of the bulbs.

Earl, I redid all the contact points, both ground and power, no luck. Thanks anyways. I think I can rule that out now.