I have a 1986 560sl, engine has high RPM after warm-up,was told could be overload protection or it's fuse,where is it located?

the relay is above the fusebox, behind the cardboard. you have to pull the sill plate off to get the panel out.

when you get the relay out, look at the date. if it's older than 8 years, replace it. the fuse is PROBABLY ok, the relays don't age well. even if the fuse is blown, replacing just that won't be enough. did it enough times 25 years or so ago to find a new relay is the repair. good luck, chuck.

The relay is above the fuse block behind passenger side right kick panel. You can see it but probably can't unplug/replug without removing the kick panel.