Water ingress into the SAM is very common, especially in Roadsters. Water can get held between the small
components, causing a short circuit. Extended water introduction can start to corrode the PCB and components.
The water eventually evaporates leaving limescale deposits which still hold some moisture however,
the limescale can also carry corroded copper causing a continuous short circuit.
If you start experiencing electrical issues with your smart (especially Roadster), get the SAM out and at least
inspect it because, the quicker you get to the problem, the less chance you have of unrepairable damage.
Cleaning it or leaving it could be the difference between 1 can of electrical cleaner or a new SAM unit.
Swing the SAM unit down and disconnect it from the hinge end. Disconnect all of the electrical connectors.
Take the SAM unit to your designated workspace and pull out the 4 large fuses from the top of the SAM.
Use a Torx 10 screwdriver to remove the screws (depends on the SAM unit if they are there).
The go around the outside edge of the SAM unit and unclip all of the clips...
...so the top comes off.
On both sides are a pair of clips, push these in and lift the SAM unit PCB out.
Look into the 2 multipin connectors. (They are called 40 pin connections but they only have 30 active pins).
You may notice signs of current or previous water ingress like this.