Missing an arm?

[AGod]

My car feels like it is only firing on a couple of cylinders (as there's hardly any power even when the pedal is fully down, resulting in very slow acceleration, but then it does gradually pick up speed) so to start off I’m, planning on removing the dizzy caps to give them a clean, or replace if necessary. Whilst under the hood I noticed a couple ball joints that I feel should be connected? The arrow points to the rod that comes from the throttle assembly and as it turns (when the accelerator pedal is pressed) it moves the nearest ball joint. My question is….. should there be an arm that links both the ball joints?

Model: 1990 500SL

 

[AGod]

I've just seen a couple of YouTube clips and they quite clearly show there is a linkage arm which is missing from my car. I would appreciate if someone could give me the part number for this?

 

[Druk]

Looks like it may be the cruise control motor that's been disconnected from the rest of the linkage. Can you confirm if the car has cruise and does it work?

 

[AGod]

Thanks for your comment Druk - yes it does have cruise control. I shall test it this weekend..