1981-1991 S-Class Cruise Amplifier Location (126 Chassis)
126 Location Description:
These units are located to the left of the brake pedal assembly.  Photo on the left is take from a 1982 300SD with the cruise unit removed. The cruise unit sits inside the red circle. In later models you might find some duct work in the way. Most cases you can remove this duct work without problems as it is just force-fit into its two connection points. 


126 Removal Tip:
Remove the 10 mm bolt that is holding the bracket in place. This will be much easier than attempting to get a screw driver in that area to remove the Phillips head screws.

  
Note on 1985+ Cars
On cars made after 1985, the amplifier is much easier to remove. You do not need to remove the whole bracket. There is a clip on the front edge of the cruise amplifier (closest to your seat) that can be removed allowing the amplifier to be dismounted. Left is a photo of the bracket and clip.
 

1986-1995 E-Class Cruise Amplifier Location (124 Chassis)

124 Location Description:

You'll first have to remove the driver's side lower dash piece. The 124's cruise control is located just to the left of the steering column. It is mounted on a bracket which is held in by two bolts (indicated by the blue lines in the photo. Once you remove these bolts you'll be able to access the amplifier easily.  Note that the cruise controls that I service might not be installed on all models. Around 1993 Mercedes switched to a different engine management system and some cars cruise control were routed to it (typically 300/400/500E). If you are in doubt, drop me an email with your VIN and I can check for you. 
 


Late Model Location (from ~1989)

1984-1993 190E Series Cruise Amplifier Location (201 Chassis)

201 Location Description
The 190E/D's cruise unit is, by far, one of the easier units to access. Across all years and models the cruise amplifier is located in the passenger side foot well.Simply remove the passenger side floor matting. Remove the plastic panel at the passenger's feet and that silver aluminum box is the cruise unit.

On early models (pre 1989) the cruise control amplifier is reverse mounted to the metal panel shown in the  top left photo. Amplifier removal requires that the entire plate be unbolted and removed. Phillips heat screws hold the amplifier in place from behind. 

On the late models (1989+) the amplifier can be removed without having to remove the metal panel. 

1971-1989 SL/SLC Roadster Series Cruise Amplifier Location (R107 Chassis)  

107 Location Description:

The 107 chassis cars amplifier is located just to the left of the brake pedal assembly. Its best removed by taking out the 10mm bolt that holds the bracket to the pedal assembly.  It is similar to the 126 and 123 chassis locations. Unfortunately I do not have a picture of this area yet. Hopefully the 123 and 126 photos will be of assistance.

1990-1995 SL Roadster Series Cruise Amplifier Location (R129 Chassis)

129 Location Description:

The early 129 roasters have their amplifier installed in a box that is located on the passenger side of the engine bay. Click the image on the left to open a larger image. The module is in at the left most side of the box. 

There is a black cover on top of the box, once opened it should reveal a number of modules, one of which is the 007 type plastic housing cruise control unit. 

 

 1975-1986 123 Chassis Cruise Amplifier Location (123 Chassis)

123 Location Description:

The 123 chassis cars amplifier is located just to the left of the brake pedal assembly. Its best removed by taking out the 10mm bolt that holds the bracket to the pedal assembly. The photo on the left is from a 123 300TD station wagon. But I think its similar for all the 123 chassis cars.