In the kit you should have a cable with a plastic connector on one side, and 3 metal terminals on the other.
You will need a cruise control stalk which can be bought from a dealer or on eBay in UK under part numbers below. 450 Cabrio and 452: 0012540V004 or 450: 0012539V004
The plastic connector connects to the Cruise Control Stalk on your car, and the terminals connect to the SAM unit.
To get to the cruise control stalk, you need to remove 4 – Torx T10 bolts under your steering wheel.
Once you remove the lower and upper panels held by the 4 bolts, you should have access to the cruise control stalk.
The red arrow on the photo points to the connector where your new wiring – plastic plug will go.
You can route three terminals to the sam unit behind the stalk all the way down to the drivers feet.
The SAM unit lives just above your throttle and brake pedals and looks like this.
And that’s how it looks just above the pedals.
It is held by a couple of bolts and plastic clips. To get access to the plugs you can either undo the plastic clip and hinge it down, or you can unscrew the bolts and remove it further down for even easier access.
We will be working with two connectors above and adding 3 new terminals. Grey Connector is called N11-9 and the Black one is known as N11-8. They look the same shape, but you will not be able to mix them up. They have unique tabs.
Now that we have the two connectors out. We need to remove their cores. You can use a small screwdriver to pull a tab and push from another side.
On both of the connectors we will be working with the grey core only. If you look closer the core will have small numbers in the corners to indicate which pin is where.
Now let’s connect the terminals on your new wiring to the correct pins. Orientate the terminals correctly when inserting, they should make a satisfying click when inside and locked.
Pink – Red cable: Connects to the N11-8 (White) plug; remove the Grey Core and insert it into Pin 7.
Green Blue cable: Connects to the N11-8 (White) plug; remove the Grey Core and insert into Pin 10
You are now done with N11-8 and can reassemble it back.
Black – Green: Connects to the N11-9 (Black); remove the Grey Core and insert the into Pin 11
That’s it. You are now done. You can clip SAM unit back in and screw the panels around the steering wheel back on.
Now you need to program the new Cruise Control using Xentry machine. Most of Mercedes/Smart indie garages have it and will generate the right TAN code. Most of the time they can do it for free. You can also ask on your local Facebook fan club if anyone has Xentry. Sometimes people bring it with them on Smart Roadster meets :).