My directional signals are not working, neither inside or out.

They just stopped working. Is it a bulb or wire? Any suggestions?

I have had the same problem in my 1975 450 sl (W107) The fuse panel is on the right side of the passenger side compartment just in front co the door. By removing the fuse for the direction signals and replacing it with a new one ( the old one still looked good ) They came back on. I hope this helps. By the way, the 450 sl and the 560 sl share the same body stile

If they come on solid, but don't flash, that is either a bulb or the flasher module. If they don't work at all, then the first thing you need to check is the fuse. If the fuse is good, your switch may be bad. I don't know where the fuse panel is on the SL, but the flasher unit should be right next to it. Sorry, I've only had E's and an ML.

OK I had this problem fixed on a 380SEC (a W126) about 6 months ago. In cold weather the turn signals did not work, but the hazard flashers did. (Sounds crazy, but that was the fact, when the day warmed up, the turns signals started to work.)

If your hazard flashers work the fuse is probably OK and the relay is OK. (presuming it's the same fuse and relay as the turn signals). Replace the fuse in any case, the fuses used in the W126 can look OK but really be blown. On my car it is a 25 ampere fuse but check what it should be on yours. If this does not fix the problem, it is the switch attached to the steering column or it is the plug and socket muti-pin connector between the switch and the rest of the wiring. This is buried under the shroud around the top of the steering column.

On my car the plug had begun to come loose and contraction of the pins in the cold made them lose contact. The cure was to squeeze the connector together again. To do this you will have to remove the steering wheel (air bag?) and the plastic shroud around the upper steering column to get at either the switch or the connector.

Though my '83 380 has no air bags, I could not get the steering wheel off. It is held on by something like a big Allen screw and even with the correct hexagonal thingy and a torque wrench I could not shift it, and neither could the auto electricians when I finally gave up and took the car to them - they had to take it to another workshop.

The turn signal relay is behind the speedometer/tachometer gauges on my car and is bolted via a bracket to the body or the steering column. (I can't remember which.) To get the relay out you do not need to remove the steering wheel but you can take the speedo assembly out and work through there.

To get the speedo assembly out, bend short hooks maybe 1/4 ince (5mm) into two pieces of straight wire cut from a clothes hanger about 6 inches (150mm) long. Make bigger hooks at the other end to get your fingers under. Disconnect battery. Slide the short hooks in between the speedo assembly panel and the hooded bit of the dashboard at the ends and hook the back of the speedo assembly. Then pull.

The speedo assembly is actually just jammed in place and is not held in by clips or screws etc. If you note where each wire and lamp goes you can remove the speedo assembly entirely. (Digital photo might help in getting everything right).

To replace the relay you will have to remove multiple ground wires bolted to the body work which are in the way. This is a slow business but not difficult. That is, if your 560SL is laid out like an older SEC.